Riders Of Vision

General => TechTalk => Topic started by: Walt_M. on May 18, 2016, 06:09:43 AM

Title: FZR carb conversion
Post by: Walt_M. on May 18, 2016, 06:09:43 AM
Well, I finally got my '83 into my shop. I have been finishing suspension and brake mods on my RZ so it has taken quite a while to get started. My immediate problem was a result of ethanol gas dissolving my redcoat tank liner and depositing it in my carbs. I am not sure what I am going to do about it. My first thought was to do a carb swap to some FZR600 carbs I happened to have lying around. This looked good at first but now that the bike is in the shop with the carbs, it looks like they may not fit. If that is the case, I will have to get the '83 carbs clean. Not sure where to start but I may try a short soak in E85. When I get the carb problem solved, I am switching over to an R1 electric fuel pump, also on hand. My last mod will be to try my 650 Turbo forks. I have had them a long time and it is time to see if they will fit. If I have any success, I will post in Tech Talk. Don't expect anything too fast. I am getting my left knee 'scoped next Tuesday so I don't know how well I will be moving after. On the positive side, the surgery is why I put the bike in the shop now.
Title: Re: FZR carb conversion
Post by: Rikugun on May 18, 2016, 08:11:15 AM
This is not the first time I've heard of a tank liner dissolving and fouling the carbs. It sounds like a real mess. I don't have any first hand experience with this so no good advice either.

How does this happen? Is it from continual use or is it more of an issue when the bike sits dormant for a long time with the tank topped off?

Good luck with the knee surgery and hope you're back on your feet soon. I'll be looking forward to your posts in the Tech section.
Title: Re: FZR carb conversion
Post by: Walt_M. on May 18, 2016, 02:54:43 PM
I think the tank liner is going to dissolve regardless of use but the carb issue may not have come up with daily use. However, I parked it when the tank started leaking. I was just too slow taking care of the leak and one problem became two. I forgot to mention I have a new '82 tank I am going to use. Also have a NOS petcock for the tank. My wife has long stopped complaining about me being a packrat.
Thanks for the good wishes about the surgery. The Dr. thinks it is a torn meniscus. I sure hope he can fix it.
Title: Re: FZR carb conversion
Post by: Walt_M. on May 29, 2016, 06:34:55 PM
Got my carburetors off this morning, it still requires a great deal of cursing. Even more so when I broke the little nylon drain fitting off. Guess I was tired and forgot the damned thing. Probably did not help that my knee is still pretty stiff. The throttles are nearly frozen and finally turned with some effort. I am more optimistic that the FZR carbs will fit but it will take some time.
Title: Re: FZR carb conversion
Post by: fret not on May 30, 2016, 01:10:44 AM
Here is wishing you full success with the 'new' carbs. :angel:  If they work this will be a real step forward.
Title: Re: FZR carb conversion
Post by: Walt_M. on June 06, 2016, 06:30:13 AM
I am still futzing around with carburetors. The FZ carburetors will need to set up about a half inch from the manifold to clear the frame brace in the rear. Briefly thought about going back to the stock carbs but then I opened them up. Looks like the bilge in a tramp steamer! I might be able to get them clean but it will be last resort.
Title: Re: FZR carb conversion
Post by: Walt_M. on June 19, 2016, 12:55:14 PM
I am making grudging progress. I have chosen 2 carbs to use, the left will be the front and the 3rd will be the rear. It has the throttle bellcrank and idle stop. I made some adapters to space the carbs up about an inch and am about ready to see if it will start. I don't have the throttles joined but I just want to hear it fire.
Title: Re: FZR carb conversion
Post by: QBS on June 19, 2016, 06:00:18 PM
I'm excited.  Can't wait for a results report.
Title: Re: FZR carb conversion
Post by: Walt_M. on June 19, 2016, 06:57:17 PM
It ran today, for about three seconds, but it is another step. Stopped by fuel leaks. FWIW if the carburetors don't have to be raised any more, I won't need a fuel pump.
Title: Re: FZR carb conversion
Post by: Rikugun on June 20, 2016, 07:12:57 AM
FWIW if the carburetors don't have to be raised any more, I won't need a fuel pump.

Gravity seems to work well despite being just a theory.  ;)
Title: Re: FZR carb conversion
Post by: Walt_M. on June 20, 2016, 03:13:22 PM
It runs, at least on the front cylinder. I think I have a vacuum leak on the rear. Now I need to connect the throttles and chokes.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 01, 2016, 05:50:13 PM
I made solid progress on my carburetors today. I have them bolted together with functioning throttles. I will post some photos when I get back to it. Choke linkage is next.
Okay, I have photos. The first two show the way they are bolted together. Tried to show the way I connected the throttles. The fourth is the carburetors on top of the frame rails, then the carburetors in place, easy fit between the frame rails. Right side view then back out. Took about five minutes from out to in to back out. I am loving this.
Title: Re: FZR carb conversion
Post by: fret not on July 02, 2016, 03:00:00 AM
Walt, what year bike did the 'new' carbs come from? 8)

This project is starting to look more and more promising.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 02, 2016, 05:35:00 AM
Late 80s to 96 or so. They made the FZR for 6 or 8 years. I have seen lots of these carbs on ebay. I am getting excited about getting it running. At this point I have maybe $200 invested, if you don't count the drill press that I needed anyway. The carb connectors and throttle extension are made from 3/8ths aluminum rod.
Title: Re: FZR carb conversion
Post by: Rikugun on July 02, 2016, 05:22:56 PM
I'm glad to see progress - and pictures on this.  :)
Title: Re: FZR carb conversion
Post by: ChrisV on July 03, 2016, 03:16:11 AM
This is very cool.  I can't wait to hear the outcome. 
Title: Re: FZR carb conversion
Post by: Walt_M. on July 04, 2016, 03:43:48 AM
After considerable thought, I am using the original Vision choke actuators. Made a couple of simple tabs to mount them. Just need a cable clamp. Photos to follow.
Title: Re: FZR carb conversion
Post by: Rikugun on July 04, 2016, 09:39:17 AM
I was wondering how you were going to work out the choke actuators. Seems like a good solution to use components made for the job.
Title: Re: FZR carb conversion
Post by: fret not on July 05, 2016, 12:39:05 AM
Walt, what have you come up with to connect the new carbs to the heads?  Does there seem to be enough room to make it all happen? 

I have been using the website 'Motorcycle Specifications' for comparing bikes and parts, as they have a technical sheet for each model and year.  I have found the FZR 1000 EXUP uses 38mm carbs, the FZR600 uses 34mm carbs except for some models.  I saw 37mm listed for a few.  These all seem to be for the forward leaned engine so should b e the 'downdraft' variety.  There is a mix of Kehin and Mikuni depending on the model and year.

http://www.motorcyclespecs.co.za

This is getting more interesting as the days go by.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 05, 2016, 06:33:23 AM
My carbs are 34mm. I found an electrical conduit splice for 1 1/4 inch pipe whose outer diameter fits the Vision intake and the carb, with an O ring fits the inside. Of course I had some tedious shaving down work on various ribs and flanges and ribs plus JB weld in the set screw holes. Oh, and I cut the splice in two so one splice makes two adapters. The carbs set about an inch above the intakes which is necessary for them to fit in the Vee. I realize there will be problems but if I can get it running well the intake adapter can be better sorted.
Title: Re: FZR carb conversion
Post by: fret not on July 07, 2016, 02:20:35 AM
Digging around the spec sheets I found the YZFR1 up to 2001 used 40mm Mikuni downdraft carbs.  2002 and later used fuel injection.  That is 4 of them for 1000cc engine, or one 40mm carb per 250cc cylinder.  That sounds like a LOT of carburetor, maybe even enough for one 40mm carb to feed both cylinders of a XZ550.  My thinking here is that it is easier to adjust one carb than it is to adjust two. ;)

Walt, I'm hoping very much that your carb mod is a raging success.  I think you're on to a good idea.
Title: Re: FZR carb conversion
Post by: Rikugun on July 07, 2016, 08:12:59 AM
Tuning one carb would be simpler but there may be a performance handicap even with the 40mm. There is also (potentially) a clearance issues to consider. I'd think making a 2 into one manifold would add some height that takes away from available space for air filtration in the finite space under the tank.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 07, 2016, 08:41:09 AM
My original goal was something anyone with a few tools and patience could duplicate. I am not a welder or a machinist but it would help. Also, I am not so patient as I need to be. I put the carburetors back on it yesterday, using the K&L manifolds I have had for ten years, still uncracked, and expected it to run. It wouldn't even pop! I was gutted. But when I pulled the carburetors back off, I saw I had failed to put the clamps on! Tomorrow is another day.
Title: Re: FZR carb conversion
Post by: QBS on July 07, 2016, 12:30:18 PM
Maybe a shot of Starter Fluid would get it running.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 07, 2016, 07:04:44 PM
Massive vacuum leak due to operator head in ass.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 10, 2016, 12:12:12 PM
Decided to get a battery yesterday.  I have been jumping it off the lawn tractor and just got tired of it. Went to wally world thinking I could just get a cheapie like I had done in the past.  Well it is not like it used to be. They didn't have one and the shelf where they were was marked $74.88! Wtf, over. I checked at Advance Auto parts and they had one for $50. I thought about getting a Lifepo like I did for the RZ but not now I guess.
Title: Re: FZR carb conversion
Post by: ChrisV on July 11, 2016, 02:19:57 AM
Decided to get a battery yesterday.  I have been jumping it off the lawn tractor and just got tired of it. Went to wally world thinking I could just get a cheapie like I had done in the past.  Well it is not like it used to be. They didn't have one and the shelf where they were was marked $74.88! Wtf, over. I checked at Advance Auto parts and they had one for $50. I thought about getting a Lifepo like I did for the RZ but not now I guess.

So far I have had a good experience with the LiPo I got off of amazon.  Battery tender brand. This is on my TW200.  So small and light that my battery box now has room for a small tire pump.
Title: Re: FZR carb conversion
Post by: Rikugun on July 11, 2016, 08:03:00 AM
Quote
my battery box now has room for a small tire pump.
Given the volume of those TW200 tires, probably a good idea!
Title: Re: FZR carb conversion
Post by: Walt_M. on July 11, 2016, 01:48:59 PM
IT RUNS! Got most of the air leaks taken care of and it started right up. Only had about a cup of gas in my pony tank so I didn't do any pilot screw settings or anything else but I am quite pleased. It would idle right down to maybe 500 rpm and revved to 4000. There is much yet to do but if anyone is having carb problems, this can be a solution.
Title: Re: FZR carb conversion
Post by: fret not on July 12, 2016, 01:13:13 AM
That is great news Walt!  Thank you for the inspiration you have created with this project.
Title: Re: FZR carb conversion
Post by: Rikugun on July 12, 2016, 07:43:23 AM
Very cool indeed. I'm looking forward to hearing more running test results and especially fueling manners whilst under way.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 12, 2016, 09:56:23 PM
Had to take today off but I should do a recap. My original carburetors were ruined by ethanol and redkote. The bike sat for several years. I saw the FZR carbs on another site and got a set with one broken diaphragm dome for cheap on fleabay. First look said they wouldn't fit so I let them sit in the box for a year and went back to my RZ. Had my knee problem with looming surgery and forced down time. Got some work finished on the RZ before the surgery that I would not be able to do after. Decided I could do fiddly carburetors work even if I couldn't walk. Got the Vision carburetors off and opened them up to assess and they may not be worth trying to clean, the needle valve and seat are a one piece lump. Okay what about the FZR carbs? They are unified interconnected bank, throttles, chokes fuel feeds and bowl vents. The carburetor bore spacing is far too narrow to directly bolt directly to the Vision so I have to separate them. Checked the carb fit to the intake, not close. Also there is not enough space in the vee to fit the carburetors that low. Decided I am going to continue so I ordered viton rubber rebuild kits from Thailand for the FZR carbs. Bought a variety of 'O'rings to use for my adapters. In my search for suitable pipe to make the adapters, I was looking for inch and a half aluminum conduit but found splice joints for inch and a quarter steel conduit that seemed to fit my dimensions. Got the carb rebuild kits and started rebuilding the carburetors. I only need two but which two? I wanted to use the two outboard carbs due to the extra fuel inlet on the middle pair. But the third carb has the throttle cable bellcrank and idle adjuster. So I am using the left carb as the front and third as the rear. Had to remove the throttle interconnect arm from the front carb and drilled the center of the throttle shaft so I could extend the shaft to mate with the bellcrank of the rear carb. Used the interconnect arm from the second carb for this, very careful alignment is required here for proper throttle plate positioning. For the chokes I used the linkage from the Vision carbs. I made locating tabs from aluminum. I have rethought this and need to make another tab for the front carb to mount the cable. Of course I will need a longer choke cable since the chokes are now on the lower right side. But I will cover that when I get it. More later, maybe try to get photos.
Title: Re: FZR carb conversion
Post by: ChrisV on July 13, 2016, 05:37:27 PM
Congratulations on making this work.  big +1
With this ghost exercised you may have the best running Vision on the road.  Maybe Yamaha will be so impressed they will dust off the tooling and give this motor the frame and running gear it deserves.  OK that is a bit overboard.

If I am looking at the correct carb, could you go old school and just put a knob on the end of that en-richer (choke) plunger?  Lose the whole cable mess.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 14, 2016, 06:07:58 AM
That isn't the same carb. My chokes are down and to the left. When I start it I stand on the right side, operate the choke with my left hand and push the starter with my right. Not exactly convenient. I pulled the cable out yesterday to measure it and looked some more. Did a rude and crude routing, secured it with a tyrap and got it useable. Started it and could hear a vacuum leak but it still runs. Just need to mention this, I am not working on this full time but I am so happy not to be dealing with the wretched standard carbs. I am going to make this work.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 17, 2016, 02:53:01 PM
Well, I spent a nice long session with the Vision yesterday. I got tired of the problems I was having with my pony gas tank leaking so I decided to just use my NOS '82 tank and the electric fuel pump. I got it started okay and ran it long enough to kick the cooling fan on. The pilots are far enough out that the screws have no effect but it will idle and rev. I had to adjust the throttles again as I haven't loctited the shaft extension yet. I have decided that the stock FZR jets are too lean so I am starting around Vision setup. I ordered 130, 132,5 and 135 mains. There is another jet in there in addition to the main, 62.5 so I am bumping those to 75. The pilots are 32.5 which I am upping to 40. I could not find the correct length emulsion tube or a richer needle so I am not changing anything there yet. It is running up the tab though, $54 to JetsRUs. 
Title: Re: FZR carb conversion
Post by: jefferson on July 17, 2016, 11:16:51 PM
Going by the Kevin Cameron article you should have to go leaner to get them jetted right. Each carb was serving a 150cc cyl and now they are on a 275cc cyl which sends a stronger signal and draws more fuel. Maybe it isn't an absolute though.
Title: Re: FZR carb conversion
Post by: ChrisV on July 18, 2016, 02:48:21 AM
This is a tricky question.  You may be drawing a greater volume of air, which on the same engine would create a greater vacuum and stronger venturi effect, so you would need a smaller jet.  But, the vision may be actually creating a weaker draw on the carburetor due to slower engine speeds.  This is starting to look like a kind of mathy question.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 18, 2016, 06:57:51 AM
Thanks for the input but my thinking is from my observations. While running it does not smell rich and no black smoke. The carbs are much less restrictive than the stockers so the vacuum is probably less. It is a little slow to rev from idle. I have a base to work from so I will know more when I get my jets.
Title: Re: FZR carb conversion
Post by: ChrisV on July 18, 2016, 09:28:46 AM
Again very cool project.  All kinds of impressed.
Is this going to mate up with the stock air filter or are you going to do something else?
Title: Re: FZR carb conversion
Post by: Walt_M. on July 19, 2016, 05:26:21 AM
I was planning to use the stock air box but without the flapper.  I have a Unifilter for it but I might use pods. I have the stock box and Uni on it right now,  kind of hoping the restriction might richen it up a little. I wasn't able to get anything done yesterday, emergency room day with my 92 year old father-in-law. Nothing serious, he is just old and whiney. I did find some different fittings that I might use for carb to manifold adapters. I am just now happy with the JB weld plugs I had to use for now.
By the way,  input is welcome. Right now I have a set of FZR intakes that I wanted to try but the bolt holes do not line up and the angle in different. I could maybe make adapters for the bolt holes and change the angle but it would be pretty tall and might have problems getting filters on. But I may cut the carb mounts off and clamp them to my adapters. I might get some photos but sometimes that just gets in my way.
Title: Re: FZR carb conversion
Post by: fret not on July 19, 2016, 02:34:12 PM
Walt, photos can help us see what you are actually dealing with, which may or may not help generate suggestions and ideas.  I think some of us are itching to do this mod also.

I have two sets of mostly trashed '82 carbs (broken off jet, etc.), and one set of hopefully salvageable '83 carbs.  So far I have not been able to remove the improvised plug (now an Allen bolt) where the freeze plug type cover should be.  Depending on what is under that Allen bolt these may be 'parts' carbs.  It's all heading for some improvement one way or another.

Thanks for starting this thread.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 19, 2016, 05:23:22 PM
From my present position, I would not spend 2 cents on broken or clogged standard carbs. They are too finicky at best and irreparable at worst. If you are thinking of doing this, first I suggest you get a set of FZR600 carbs so you can follow along, or lead! This will work.
Title: Re: FZR carb conversion
Post by: Prophet Of Doom on July 20, 2016, 08:52:03 AM
I don't know what model the 600 uses but here's an interesting observation... (think that I posted this one before).  The specs for the FZR750 US Model says it runs a BD34 Carb, but BDST38 on the UK Model.  The BDST38 is common as muck - Ducati Monster, Yamaha Tenere, TDM, YZF and more.  This could be an interesting possibility for a swap.


UK specs BDST38mm:

-122.5 for cylinder 1&4 and 117.5 for 2 and 3(main jets)
-Main air jet, 50.
-Pilot air jet, 125
-Pilot Jet, 42.5
-Pilot Screw, 2 1/2 turns out.
-Valve seat size, 1.6
-Start Jet, 57.5
-Fuel Level, 7.8 to 8.8mm

US model BD34mm:

-Main Jet cylinder 1&4, 107.5. Cylinders 2&3, 105.
-Main Air Jet, 65.
-Pilot Air Jet, 125.
-Pilot Jet, 15.
-Pilot Screw, 2 turns out.
-Valve seat size, 1.2.
-Starter jet, 30.
-Fuel level, 7.3-9.3mm
Title: Re: FZR carb conversion
Post by: Walt_M. on July 20, 2016, 10:27:56 AM
The US 600 uses BDST32. I have a set of BDST38s from my TDM850 and I am pretty sure they would have fitment issues on the Vision as they are physically pretty large.  But, as they are available to me here and now I will have a look.
Ok, I looked and they would be a tight fit if at all. They are too large to fit the stock intakes of course and also too large to fit in the V if they did. They would require a complex curve of the intakes as they would have to move to the left and closer centers. IMHO, too much trouble and a lot of carb for the bike.
The 34s from the 750 may fit but they are more rare in the US
Attached some photos
Title: Re: FZR carb conversion
Post by: Walt_M. on July 20, 2016, 03:01:32 PM
Adding a couple more photos
I put a 38 and a 32 side by side on my bench. The size difference is not so apparent in the photo. I took my carbs back off and put the 38s in place and got a photo plus a photo of the carb to intake offset. This is far as I am going with this.
Title: Re: FZR carb conversion
Post by: fret not on July 22, 2016, 01:29:58 AM
A set of YZF600R carbs should be on their way to me very soon, and I will begin the process too.  Hopefully they will be in decent condition.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 22, 2016, 05:10:53 AM
You will have to clean them of course. I got rebuild kits for mine but the gaskets and 'O' rings are neoprene and you may not need kits. Just pay close attention to the way the carbs are linked before you take them apart. BTW, today is 'jet' day for me. They came yesterday.
Title: Re: FZR carb conversion
Post by: ChrisV on July 23, 2016, 12:43:40 PM
So I am starting a mental list of who has a set of FZR carbs, Figure you need two which leaves you with two extra.  Soon this site will be thick with extra carbs.  ;)
Title: Re: FZR carb conversion
Post by: Walt_M. on July 23, 2016, 04:16:19 PM
I actually have only 1 whole carb as one of mine had a broken dome which is why I got them cheap. Another issue is the 3rd carb has the throttle bellcrank and idle stop. No real problem for good fabricators, which I am most assuredly not. Also, from an FZR site, some carbs have float bowl vents and some do not. Mine have vents which are a minor problem to be overcome.
Title: Re: FZR carb conversion
Post by: fret not on July 24, 2016, 03:19:01 PM
Walt, I see you have Mikuni carbs.  The ones I ordered and should arrive Thursday are Kehin.  Is the bowl vent thing associated with brand, or just specific models of carbs?

One point which has piqued my curiosity is how to set the fuel level in the float bowls, as they look like the float bowls will be at a significant angle.  This is not a concern for fuel injection systems.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 24, 2016, 05:25:40 PM
Well, you are on your own with Kehins. The bowl vent is a Mikuni thing. You will have to go to whatever bike site that uses your carbs for float level settings. Just curious though, why did you go to Kehins?
Title: Re: FZR carb conversion
Post by: fret not on July 25, 2016, 12:03:57 AM
Well, in my experience they are a good company that makes generally good stuff, and they were less expensive than the others I saw.  Carbs and shipping came to $83.

My brother has already asked what I am going to do with the "leftovers", and I told him I have another XZ and might be inclined to make a "rat" bike.  If he can really use them he will get them.  They probably will be adapted to his "Moto Rodeo Superbo" (Honda 500 Ascot V twin with other suspension and a bigger tank).  He happens to be a skilled fabricator, worked in govt. aircraft biz for quite a few years.  Also, he has a decent muffler I can adapt to my KLR650.  I don't want it to be loud but I would like to hear it.

Title: Re: FZR carb conversion
Post by: Walt_M. on July 25, 2016, 09:01:19 AM
I don't have any problem with Keihin either but the BDST Mikunis are true downdraft. Hope your Keihins are too but you are on your own with jetting, you can't help me and I can't help you.
Title: Re: FZR carb conversion
Post by: fret not on July 26, 2016, 02:05:15 AM
Carbs arrived early and in nice condition.  There is a little bit of 'dirt' on the outside but the interiors seem quite clean.  After looking them over for a while and beginning the disassembly I think this will be a serious project.  Not rocket science but a challenge.  As Walt said, there is precious little room to fit two carbs in the V, so it will take a bit of fiddling for sure. 

These carbs are from a '01 Yamaha YZF600R, so they are designed to sit at the same angle as the Mikunis that some years used.  It looks to me the throats are supposed to be about a 10 or 12 degree angle from vertical.  Same style of enriching system as the Mikunis, but different manufacture.

Now I have to figure out which hoses do what.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 29, 2016, 06:02:08 AM
Finally got back to my jets. Got them installed and got it started. Only running on the front cylinder, wtf, over? Pulled the carbs and checked the rear pilot circuit and it was okay. Put it back and same thing! Okay, now some of you know what was wrong. Correct, leaking YICS hose. Quick trip to the local auto parts and she is running on both but I had enough for the day. I want to take the YICS off but I need to ride it first.
Well, I have it running good enough to ride, if I just had the seat and tank on it. Maybe tomorrow.
Title: Re: FZR carb conversion
Post by: fret not on July 30, 2016, 01:34:55 AM
Good going, Walt!  Each step is a step closer to getting it to work right and getting a good ride. I'm hoping you have very few and only small details to work out to finish this mod.

How is your knee behaving?

Title: Re: FZR carb conversion
Post by: Walt_M. on July 30, 2016, 05:21:55 PM
I got the fuel pump hooked up today and the tank on. This is still in the testing stage but it is progress. I am going to have to use pod air filters as the carbs are about a quarter inch too low for the stock air box. But on the bright side, it looks like the fuel pump will not be needed as the float bowls are below the lowest part of the tank. I am still going to use one since I already have it connected and it works.
I plan to ride it tomorrow if my knee will let me. Maybe get some photos too.
Got my choke cable in today's mail but I am still going to put the seat on and ride it first.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 30, 2016, 07:44:55 PM
Got some photos, didn't see the fuel line kink until I saw the photos.
Title: Re: FZR carb conversion
Post by: Rikugun on July 31, 2016, 09:44:08 AM
Is that a remote idle speed cable in front of the filter? If so, I'd consider that to be another bonus to the carb swap - easier access to the idle speed adjustment screw.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 31, 2016, 10:45:24 AM
Good eye there. Yes that is the idle speed adjuster, just haven't figured where to put it.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 31, 2016, 11:52:07 AM
I just got back from my first ride with the new carburetors and I can not believe how well it ran! I am just amazed, no spitting and sputtering. No Vision stumble just smooth acceleration and steady cruise at 60. If there was a problem, it did not start right up after I got it warm. But it did start. The only problem I had is I have gotten so used to the RZ that I thought the steering head was frozen. It isn't. Maybe the new radials will help.
Title: Re: FZR carb conversion
Post by: ChrisV on July 31, 2016, 03:32:07 PM
Big thumbs up.
When is the kit going to market?
Title: Re: FZR carb conversion
Post by: QBS on July 31, 2016, 03:59:41 PM
I know is this subjective, but which setup feels more powerful?
Title: Re: FZR carb conversion
Post by: fret not on July 31, 2016, 04:15:40 PM
WOW!  A hearty CONGRATULATIONS to you Walt!  You have revolutionized the concept of the Vision for many of us. THANK YOU! 

I will try to put up some pics if I can figure out how.  My project is in the early stages yet, with some manifold fabrication to do, and I have yet to figure out what all the hoses do and if they all are needed.
Title: Re: FZR carb conversion
Post by: Walt_M. on July 31, 2016, 06:40:49 PM
QBS, can't say whether the FZR carbs up the power but it does run good and it doesn't seem at all finicky. I know I can get the idle better with pilot screw adjustments and I might go to 50 pilots to help with cold starting and running. I haven't even done a sync yet. This is to date the best thing I have done for my Vision. FWIW, I am going to take some time off, knee and domestic stuff. I ordered the pod filters and will install with the choke cable when the filters get here.
ChrisV, no plans for a kit but if I decide to get adapters made for mine I might do more than two if there is interest. The throttle coupling and spacers are well within an average mechanics capability.
Title: Re: FZR carb conversion
Post by: fret not on July 31, 2016, 10:58:19 PM
I am having "difficulty" putting pics into a post.  So far about what I can manage is to put pics in an e-Mail (good at that).  I am using a Mac, and for some reason this process is not as simple as our old Windows PC.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 01, 2016, 05:35:02 AM
Mike, look below the post window and you will see a +Attachments and other options. It is so easy even I can do it.
Title: Re: FZR carb conversion
Post by: Rikugun on August 01, 2016, 08:26:11 AM
A very successful first ride, nice going Walt.  :) It sounds like this first "shakedown" ride was sans air filters. Maybe when the pods come in adding them will help with idle and cold starts just by themselves.

Fret, as Walt mentioned, use the + Attachments and other options for pictures stored on your hard drive. There is an "Insert Image" icon along with others above the message text box but that's for pics stored on an image hosting site like Flickr or Photobucket. Just a suggestion, it might not be a bad idea to start a new thread and document your progress there.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 01, 2016, 08:52:39 AM
I had the air horns from the air box clamped on the carburetors and the air box with filter pushed down over the air horns. Not exactly sealed but some restriction. I plan to put the pods in the air box.
Title: Re: FZR carb conversion
Post by: fret not on August 02, 2016, 01:09:15 AM
Easy for YOU to say,   " It is so easy even I can do it. "  I'm good with planes, fret files, and routers, not so great with digital things.  I even got rid of a digital caliper in favor of a dial caliper because it is easier to read and doesn't ever need a battery.
I will study this uploading 'process' and make an attempt later.  I am really in the beginning state with the carbs hung in position, now I have to fabricate the connecting manifolds.  I think there is clearance for the throttle cable, and the float bowls are away from the coolant (hot) hose from the rear cylinder.

Just ordered a used shop manual for the YZF600r (Thundercat) to get a handle on how the carbs work, what hoses do what, and which ones are actually needed.  I have found that engine coolant is piped to the carbs but I hope it is not necessary for this application.  Maybe they get really hot on the original bike.  Seems pretty strange to me, but I'm not an engineer.

Walt, are you using the fuel pump or are you taking advantage of Gravity for fuel delivery?

I will take pics of the process so when I can figure out how to upload them there will be a complete documentation.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 02, 2016, 04:18:05 AM
Yes, I am using the pump. I got used to one on my TDM. Turn on the key,  listen to it tick tick tick, filling the float bowls until it stops then push the button.
Title: Re: FZR carb conversion
Post by: fret not on August 03, 2016, 12:11:18 AM
So I am assuming your fuel pump is not for a Fuel Injection system (high pressure 42psi or so), but for regular carburetors.  Do you know how much pressure it makes?  Is it from another bike?
Title: Re: FZR carb conversion
Post by: Walt_M. on August 03, 2016, 04:21:42 AM
My pump is for a carbureted R1 and obviously has a regulated shut off. I had a FZ750 that came with one which is where I got the idea. I don't know what the pressure is but it can't be more than a couple of pounds but it is enough.
Title: Re: FZR carb conversion
Post by: Rikugun on August 03, 2016, 07:45:38 AM
I'd think a pump from any bike fitted with carbs would work as they're all designed for pressures the inlet valve can handle. Some are more sophisticated than others in that if they don't realize some degree of resistance within a given time interval, they shut off. This requires several cycles of the key switch to fill empty carbs but also guards against draining the tank when an inlet valve gets stuck open by debris.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 03, 2016, 08:34:14 AM
I connected mine to the switched positive at the Signal fuse. Key off, no pump, key on, pump. And something I found by accident while I was testing, the pump does not pass fuel when it is off. A stuck float will not dump your fuel on the garage floor.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 03, 2016, 08:16:11 PM
Had an extra burst of energy this afternoon and turned my attention to tires. I took it kind of easy on my test ride because of several things and old tires was one. Since I have the tires on hand I started changing them. Got the rear wheel off and the tire off. Wasn't sure my knee would cooperate but okay so far. See if I can finish tomorrow.
Title: Re: FZR carb conversion
Post by: Rikugun on August 04, 2016, 08:56:49 AM
Changing tires is an ambitious endeavor for someone recovering from knee surgery as it often devolves into a wrestling match!  :)

Regarding your previous post and stuck inlet valves -  do you still use a vacuum actuated petcock?
Title: Re: FZR carb conversion
Post by: Walt_M. on August 04, 2016, 01:14:24 PM
Yes, I got a NOS '82 petcock a couple years ago for my '82 NOS tank. It will probably outlast me. On the tire change, I awkwardly got the rear tire off yesterday and got the rim clean enough to try the install but the grass needs mowing. At least I have a rider.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 04, 2016, 07:12:22 PM
Got the mowing done and a break then started on the tire late afternoon and I have it halfway. The easy side.  If anyone asks,  Contis are stiff!
Title: Re: FZR carb conversion
Post by: Kenny on August 05, 2016, 12:50:18 AM
      Speaking of tires and ... about six years ago I mentioned that I was planning to use some of the balancing beads (dynabeads) instead of the weights on the rim . I have them installed in the 83 Vision and the 81 XV920rh and find them working well -installation is a bit of fun as you need to put them in through the valve stem (with the core removed) , don't put them in as soon as you let the air out as the moisture from the escaping air will gum things up. I found with the weight off the wheel and the stem at the bottom You can get most in with the supplied bottle & plastic tube , I found you can speed this process up by using an electric engraving tool - the vibes help.
  Ok back to tire installation - I have Metzlers on the Vision and Bridgestone's on the 920.
      Cheers Ken S.
     
Title: Re: FZR carb conversion
Post by: Walt_M. on August 07, 2016, 03:32:23 AM
I've never tried the beads. I just got my rear Conti on and balanced yesterday,  took about 40 grams of lead which is about twice what I expected. Do you balance the wheel then add at least that much in beads? Got my old front off but ran out of steam before I got the wheel cleaned up. Tomorrow is another day.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 07, 2016, 05:03:49 PM
Got the wheel cleaned up and the tire on but it wore me out. Now if the bead will just seat. Monday update, got the tires balanced and the wheels on. Took my test ride and it is good. The handling is much better. It is still running good but with the new tires I was giving it a bit more throttle and I think I need a bit more adjustment. If it isn't the throttle it could be the main jets. I'll have to look at the plugs. Some have suggested it might be a bit rich and I may have to agree as the temperature gauge never got over halfway and it is a warm day.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 08, 2016, 03:54:59 PM
Found the throttle problem, there is a part of the FZ interconnect that I left on the rear of the rear carb. I left it because I needed the spacer on the throttle shaft and I didn't see it hitting the frame brace. I will be cutting the ear off that and putting it back. The plugs may be a little sooty but I am not changing the jetting yet. I still want 50 pilots so back to jetsrus and I might get some leaner mains too.
Title: Re: FZR carb conversion
Post by: fret not on August 09, 2016, 02:24:51 AM
Each step is a step closer to the destination.  By the way, how is your knee ?  You must be a pretty tough person to continue wrestling with tires and carburetors with a healing knee.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 09, 2016, 04:11:28 AM
I wish the knee was coming along as well as the bike. They fixed the main problem which was a torn meniscus. Part of it was getting pinched when I took a step, made me want to fall down and pee. But that doesn't happen any more. I just want it to get better than it is now.
Title: Re: FZR carb conversion
Post by: Kenny on August 09, 2016, 08:59:42 PM
  Hi Walt,
  You were asking about the weight of or number of beads required to balance your tires , I don't have the paperwork from  the setup I used but I remember a chart that recommended the required amount according to the size of the tire. I believe their web site also has this information. A large truck tire would require more beads to do the balancing than a motorcycle tire assy.
     Cheers Ken S. 
.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 11, 2016, 03:52:23 PM
I got it back together this afternoon. Have the choke cable connected and the pod filters in the stock air box, still no flapper. It is much easier to start with the remote choke. I was going to try it without the fuel pump but that will come later. I have realized that although I really like the pump, since fuel doesn't flow if it isn't running, if the pump quits the bike stops. That could be very inconvenient, especially in traffic.
Title: Re: FZR carb conversion
Post by: fret not on August 12, 2016, 01:29:43 AM
Walt, are your float bowls lower than the original ones?  If they are maybe gravity will suffice, but if they are the same height or higher you will need a pump. 

I am planning on using a 12V fuel pump because my 'new' float bowls will be a bit higher than the ones in the original carbs.  Just plain old Gravity would be sooo much easier.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 12, 2016, 04:20:16 AM
Yes, the float bowls are below the bottom of the tank. You can sort of see it in the photos on post 57.
Title: Re: FZR carb conversion
Post by: Rikugun on August 12, 2016, 10:03:05 AM
Regarding eliminating the electric fuel pump - if it will work without it I'd say go for it. Simplicity and reliability often go hand in hand. Good to hear you got the remote choke connected. Having owned bikes without that feature I think I prefer to have it on the bars.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 12, 2016, 02:38:41 PM
If I were doing this mod and did not already have a pump, I would not get one. However as I had it and it works I decided to go ahead and wire it in. I let my bikes set too long between rides and it makes it a hell of a lot easier to start. If the pump fails out on the road I can connect the fuel line around it and ride on.
Title: Re: FZR carb conversion
Post by: fret not on August 12, 2016, 10:07:08 PM
Walt, you are an inspiration to us all, and thank you for that.

I have not put my tank on in comparison to the position of the carbs yet to see if they are lower than the petcock.  If I can avoid it I will not use a pump, but Reality being what it is, I will take cues from what I see as my 'system' 'falls into place'.

The carbs I have are from a '01 YZF600R Thundercat.  In the Haines manual it is stated that Yamaha went to another induction system because of the expensive carbs on the YZF600R.  So, I don't know if they are better than others or just more expensive.  In the final analysis it is the function, not the cost of carburetors.  Maybe.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 14, 2016, 11:25:29 AM
I just got back from a very unsatisfactory test ride. I don't think it likes the pod filters. It just seemed to flatten out at 5K. Also had it die on me at the last stop sign before home, had a YICS hose pop off the rear cylinder. Guess I'll have to start clamping them. I haven't looked at the plugs yet but the exhaust pipes are noticeably black. I got 127.5 mains so I am going to try them next but I suspect that may not be enough. I will get it but it just takes time.
Title: Re: FZR carb conversion
Post by: fret not on August 14, 2016, 03:06:18 PM
Smooth 'laminar' air flow is important for the intake.  I recall Treedragon stating he got better power when he lengthened the stock inlet "horns" on the carbs.  The carbs I have came with fairly long plastic "horns"(factory issue) to smooth the air flow. 

The factories have gone to significant lengths to develop air boxes for the intake.  Pod filters have not been recommended for the stock carbs because of lesser performance,  so maybe I see a correlation  between pods and your new carbs.  The pods keep debris from entering the carbs but don't seem to help smooth the air flow.

I ordered some mild steel mandrel bends to make 'manifolds' for my 'new' carbs.  I will be making a file of pics to document the process, and will try to put it all together in another thread when it happens.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 14, 2016, 04:32:43 PM
Mike, you are probably right about the air flow and I will go back to the stock filter and air horns. I just need to get it sealed better than I had it. Probably go to the 127.5 mains as I did think it was rich last time. I will keep posting. 
Title: Re: FZR carb conversion
Post by: Prophet Of Doom on August 15, 2016, 08:35:22 AM
The XZ400 comes with two different length velocity stack - about an inch longer and a bit curved on the front.  Generally speaking longer gives better low down power, shorter, up top I've read, so perhaps an attempt at getting both?  The XZ does something similar with valve cams also with different on front and rear.


There are calculators on the web about how long to make velocity stacks for a given RPM and carb diameter. 



Given that RPM changes all the time I was musing a while back about the idea of building a servo driven velocity stack for the XZ that would always be the optimum length.  The R1 does this I think.


Title: Re: FZR carb conversion
Post by: Walt_M. on August 17, 2016, 12:34:33 PM
Got my test ride in this morning and it is a lot better but now it is rich down low. I had it to 8K which is actually fast enough for the street but it is sluggish below 4K. I think I will go back to the 60 starter jet as I am not exactly sure where it comes into play. The needle jet is not notched but it does have a washer under it so I might drop the needle too. And,  Mike, FWIW, you might want to just try the stock FZR jetting in your Keihins first. It might be pretty close. I am starting to get some money invested in jets that I may never need. At $7.50 apiece it adds up.
Title: Re: FZR carb conversion
Post by: ChrisV on August 17, 2016, 09:33:18 PM
Sounds like you might want to do a couple of these.
http://www.ebay.com/itm/like/262404550401?lpid=82&chn=ps&ul_noapp=true
some of the smallest ones could be drilled out to larger than 125 if needed,
Just an idea
Title: Re: FZR carb conversion
Post by: fret not on August 18, 2016, 01:51:42 AM
Chris, generally it is not a good idea to drill jets unless you are in a tight spot and it is the only way out.  Jets are very carefully machined so they have no burrs or irregular surfaces to disturb their ability to flow fluids.  Even pushing a wire through a jet can scratch it and change it's flow rate.  Now, since Walt is a machinist I am sure he is aware of this and may well be able to manage altering jets, but then they need to be marked as to their new capacity.  Tiny jets are rather difficult to read the numbers let alone re-marking them to another value.  It's better to have factory marked jets so you can make informed adjustments. :police:

Getting old kinda sucks sometimes.

Walt, I had figured to start with factory jetting, hoping it will be close, but I know that changes may well be required.

My mandrel bends arrived today, so cutting and fitting will soon begin.  But before that I will be helping my brother get his slat flats bike prepared to run Sept. 10 - 13. (Suzuki T500 Partial Streamlined/ Fuel)
Title: Re: FZR carb conversion
Post by: Rikugun on August 18, 2016, 10:57:40 AM
I agree with all the warnings regarding jet drilling but have gone ahead and done it anyway on more than one occasion with good results. Jets can be quite pricey and it's unlikely you'll have every size and style available so drilling can be a viable option and sometimes necessary in a practical real world sense.

Jets I've drilled are kept in a separate plastic bin since I don't try to mark them. Prior to drilling I use the drills as go/no-go gages to establish a baseline size. You can use the same technique on unmolested jets of different sizes to then compare against drilled ones to roughly gage it's size.

One of the pitfalls is drilling too much. The first time this happened I soldered the jet closed and redrilled. This was admittedly an act of desperation as I was stuck with no immediate options but it worked very well. I employed this technique again this past winter on my snow thrower. I foolishly tried to jet a problem away that I sensed had nothing to do with carburation. Since I had gaged the sizes prior to drilling I was able to return them nearly to their factory state after fixing the real problem. I say "nearly" because it has fixed jets and always ran a bit lean. Well it doesn't anymore and now runs better than it ever has. Don't tell the EPA.  ;)
Title: Re: FZR carb conversion
Post by: Walt_M. on August 19, 2016, 04:21:56 AM
Well, I almost blew it up yesterday. I put the 32.5 pilots and 52.5 starter jets back in. I don't have a very good throttle cable setup so I have to do a crude cable position adjustment when I put the carbs back on which involves WOT with the throttle lock on. I am kind of amazed that it started with the throttle wide open! Got it shut off with no immediate damage. Restarted it when my heart rate returned to normal but I decided to wait for the test ride.
Title: Re: FZR carb conversion
Post by: Rikugun on August 19, 2016, 10:02:19 AM
I'm guessing that was an exciting and horrifying few seconds that seemed longer as it was happening.  :)
Title: Re: FZR carb conversion
Post by: Walt_M. on August 22, 2016, 11:17:20 AM
Finally got my test ride in this morning and I am happy to say that I now have a runner. It starts well, accelerates well. Steady state cruise is good with no surging or stumble. The brakes are good enough with the EBC pads and I am happy with the handling with the new Conti radials is very nimble and not at all twitchy. I still have plenty to do, it is still a Vision, but I can ride it as it is.
Title: Re: FZR carb conversion
Post by: fret not on August 24, 2016, 01:22:58 AM
Walt, that must be a huge relief to have accomplished your goal.  That's a big mountain to climb, and you did it!  You have put some fuel on the fire for the rest of us to get busy and just make it happen. 

Right now I have some parts and pieces, and I'm definitely heading up the mountain, but by a slightly different path since I have different carbs and elected to make the manifolds fit the carbs. 
Title: Re: FZR carb conversion
Post by: Rikugun on August 24, 2016, 08:49:43 AM
Nice work Walt, I'm glad it's worked out. Nothing left to do now but put miles on it!  :)  Oh, and fix any of the other Vision peccadillos.

Title: Re: FZR carb conversion
Post by: Walt_M. on August 24, 2016, 01:15:23 PM
Well, there is always the R/R. I think I will try the series type as I don't believe going to a MOSFET would do anything for the stator.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 29, 2016, 06:23:34 AM
A mind is a terrible thing. I got bored yesterday and disconnected my fuel pump. Put it on prime for a minute or two and it started right up. I guess I don't really need it unless for really low fuel level. It has less than 2 gallons in it now but it is not on reserve.
Decisions, decisions. I have determined that the pump will not pass fuel if it fails but it may not be able to use the last bit of fuel without it.
I think I will keep the pump since I already have it. All I really need to do is get it mounted better. If it fails out on the road, it would take very little to disconnect it and be on my way.
Later this morning I was doing some pilot screw adjustments and was not having much success. It finally started slowing down and as I was adjusting the idle speed up, it stopped. Carburetors are empty. Put it on reserve and reconnected the pump, put it on prime and it started right up. Futzed with it some more. Side note, it is very to reach the throttle balance adjuster screw with my setup. Anyway, I got it where I wanted it and took it for a test ride. I wanted to try something with the air box. I was going to punch some holes in it but as I would have to fix it if it didn't work, I just left the top off and tie wrapped the filter in place. The ride was short and loud. I can say it ran okay but probably not better. At this point, I am going to run the air box top undrilled and go another step or two leaner on the mains.
Title: Re: FZR carb conversion
Post by: fret not on August 30, 2016, 01:12:32 AM
The air box and filter help keep the intake noise down a bit, so I would vote for keeping them in place, at least until you can come up with a more efficient set up.
Title: Re: FZR carb conversion
Post by: Walt_M. on August 30, 2016, 05:23:10 AM
It was truly annoying so the top goes back on. It is a non-modified '82 top with the flapper completely removed. I like the design of the thing and am not convinced that it needs a bigger opening. I am going to go leaner on the mains but I'm not sure how much, just wish they weren't so expensive and I didn't have to order them.
Title: Re: FZR carb conversion
Post by: Walt_M. on September 18, 2016, 03:07:42 PM
Finally made some progress, front brakes this time. I got a set of the blue/gold spot caliper adapters and a set of gold spot calipers. Had some scary moments with fit but I got them on and I have to say it was worth it. I used the stock Vision master cylinder and it gives good feel with one-finger power. This thing is getting to be a pretty good motorcycle! I did put the stock air box top on, just cut the standard opening a little bit and it ran good and I am happy with the return of the quiet intake.
Title: Re: FZR carb conversion
Post by: fret not on September 18, 2016, 04:47:50 PM
So it sounds like things are really coming together nicely.  Congratulations to you for your accomplishments!   :)
Title: Re: FZR carb conversion
Post by: Rikugun on September 19, 2016, 08:29:13 AM
It's amazing how the simple things can really make the difference in enjoyment. And when I say "simple things", in the case of motorcycles I mean brakes that work and carbs that fuel properly.  :D
Title: Re: FZR carb conversion
Post by: Walt_M. on September 19, 2016, 10:55:25 AM
Also can't leave out the radial tires. As I had previously stated, I had never run a 90/90 front. It is an '83 and came with a 100/90 and due to what I considered excessive wear, I went to a 110/90. Can't say much about the wear but it handled like a truck. Now it is a joy to ride. It is both agile and stable, I really would like to have a set on my RZ.
Title: Re: FZR carb conversion
Post by: QBS on September 19, 2016, 02:24:13 PM
Walt, thank you for your commitment to your journey and bringing us along on the adventure.  You have seen it through to the end (if such journeys ever have an end).  I am happy for you and look forward to whatever new developments may unfold.  Thank you!  Well done.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 19, 2016, 11:24:52 PM
Wow! How did I miss this thread? I recently finished my own FZR carb transplant on my 82. Starts easily, idles nicely, no stumble or hesitation, accelerates really hard and pulls to redline (and beyond). Haven't checked the fuel mileage yet due to refining the jetting and generally riding it pretty much wide open during testing. Amazing how much nicer it is to ride.
Title: Re: FZR carb conversion
Post by: fret not on September 20, 2016, 01:26:54 AM
Ron, how close to the way Walt did his is your installation?  A write up of your process will be welcomed, and may help others to do much the same.  Pics too please. :)
Title: Re: FZR carb conversion
Post by: QBS on September 20, 2016, 11:13:24 AM
Ron, I'm particularly interested in knowing about your manifold solution.  Pictures please.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 20, 2016, 01:34:02 PM
I machined aluminum adapters to plug into the vision rubber manifolds with the upper diameter the same as the FZR carburetor throat o.d. And connected them with 1 1/2 " Gates fuel proof hose, the type of hose that connects the filler tube to the gas tank on a car. Also velocity stacks to adapt to the rubber velocity stacks in the stock air box. Meantime I moved to another town and this project got dropped for a while. The vision sat for a while due to a starting problem and misfire at low speed which ended up being a defective pickup. Once I got it going again, I fabbed cable stops for the throttle and choke and worked out the plumbing on a spare engine I have on an engine stand, which made things a lot easier. Much of the installation resembles Walt's from what I can see from his pictures, tubular spacers and so forth. Mounted my cable stops on the spacers and sectioned and welded the FZR choke linkage. I used the vision throttle and choke cables. Next time I have it apart, I'll take some pictures and post them. Right now I want to do some riding before I tear it apart again.

Congratulations Walt. Quite an accomplishment on this bike. This is how Yamaha should have done it in the first place.
Also did the series rr installation. 14.2 volts at idle, 14.6 at 3000 rpm. Rr is up in the fairing. Rr Temp dropped from 130 degrees to 105. Stator case at 180 degrees after 40+ miles of canyon riding on 98 degree day.
Title: Re: FZR carb conversion
Post by: Walt_M. on September 20, 2016, 07:29:25 PM
Ron, it sounds like you preceded me with this swap. I am sure your machined adapters are nicer than the things I made but it is the same principle. I am very interested in your jetting. I had some sir leaks at first that led me to think I needed to go richer and I did. As I have stated it is rideable now but it could be better. Did you keep the fuel pump? I do appreciate the info on the series R/R, encourages me that it is worth doing too.   
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 20, 2016, 10:51:08 PM
Walt, I have #35 pilot jets, #135 main jets and the starter jets that came with the carburetors. I'm running the stock fuel pump. I started off without it, but got to thinking about low fuel levels and it was easy to mount the pump. I haven't done an engine kill plug check yet due to how much fun it is to pull a plug on the side of the road, but it pulls cleanly past redline in the lower 4 gears(haven't done a top speed check yet) with euro gearing and runs just below center on the temperature gauge.
I think the series rr is a good thing. I was running over 15.5 volts at speed with the vision rr. The engine in my bike now has just over 17,000 miles on it and is still on its original stator which looked pretty good when I changed out ignition pickups. I live in the mountains about 4 miles from a small town( 6 stop lights ) so most of my riding involves a lot of miles and little traffic.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 20, 2016, 10:55:03 PM
Have to add that elevation where I live is right at 4000 ft. 20 miles west its down to 600 ft and same distance east around 2500 ft.
Title: Re: FZR carb conversion
Post by: Walt_M. on September 21, 2016, 06:05:39 AM
Ron I was very surprised to see your jetting numbers, especially now that I see your elevation. I am at sea level and it was really rich with 130 mains but I also had 75 starter jets and 40 pilots. I went to 127.5 mains, the 62.5 starters and 32.5 pilots that came in the carbs and it is running pretty good now except for the idle. So, having just gone over what I wrote, it looks like my problem was the 75 starter jets. Looks like plug checks are in order but it is still hot here in Florida so that is not much fun.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 21, 2016, 09:16:30 AM
Walt, I started with 127.5 mains and 32.5 pilots  and 52.5 starter jets and worked from there. Still hot in California too. Going riding with friend this morning. Should ,at least get gas mileage info today.
Title: Re: FZR carb conversion
Post by: Walt_M. on September 21, 2016, 04:53:41 PM
Got a better set of eyes on my starter jets and they are 52.5 so we are together there. Went ahead and changed my sparkplugs so I will be ready for a plug check. I forgot to ask what exhaust you have, I have a Spec II on mine. When I got it 30 years ago, they recommended no jetting changes and it didn't seem to need any.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 21, 2016, 05:10:56 PM
I thought about the exhaust after I left this morning. Mine is one I built several years ago, basically a 4 into 2 into one much like a Spec ll with a muffler I built too.  I rode 140 miles today. Put gas in after the first 58 miles which was mostly an all out race with a couple of 2016 R 1200 RT BMWs over a twisty mountain road with a lot of elevation change. That worked out to right at 45 mpg. After a less aggressive ride down Kern River Canyon and back to Tehachapi, the next check worked out to an even 50 mpg. Best I've ever gotten with a Vision.
Title: Re: FZR carb conversion
Post by: fret not on September 22, 2016, 01:26:13 AM
Ron, I am assuming you have Mikuni carbs, like Walt has.

This is getting good. 
Title: Re: FZR carb conversion
Post by: Ron_McCoy on September 22, 2016, 01:15:01 PM
Mike, same carbs as Walt.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 05, 2016, 01:36:42 PM
Some pictures.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 05, 2016, 01:42:55 PM
More pics. Jetting now: 130 main jets, 32.5 pilot jets, 52.5 starter jets. Starts right up, excellent throttle response, mileage  in the 50s. Runs so good it seems even more low geared even with Euro gearing. Really happy with this mod. I wish I had finished this years ago.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 05, 2016, 01:44:56 PM
More pics
Title: Re: FZR carb conversion
Post by: jefferson on November 07, 2016, 10:53:07 PM
Can you guys explain to me the starter jet you are talking about and where it is on the carb? Is it's purpose for when the choke is on?
I was relaying your jetting specs to the friend of mine who used vmax carbs on his bike which I think are also 34mm and both of us were a little stumped on the starter jet. I was thinking that the jetting should come out about the same since they are both 34's, but you never know. He thinks his pilots are up around 60 although his mains are the same as yours.
The main difference seems to be the vmax carbs just needed to be spread apart more to fit and they fit right into the manifolds. He took them off when he was having running problems and reinstalled the stockers. That really didn't fix anything and it turned out one of his plugs had gone bad. If he gets the vmax setup back on the bike it may run much better now.
Title: Re: FZR carb conversion
Post by: Walt_M. on November 08, 2016, 04:01:15 AM
The starter jet is in the float bowl in the BDST carb. There is what I call a jet tower and it has the main, pilot and starter jet. I believe the starter jet is what feeds the richening circuit but I have not followed the plumbing to be sure. I had not considered vmax carbs but I guess I should have. The FZR carbs do not fit the manifolds but even if they did, they will not clear the cylinder head.
Title: Re: FZR carb conversion
Post by: fret not on November 10, 2016, 02:10:21 AM
Ron, your pictures are inspiring.  I am about half way to making the 'new' carbs fit my '82, though I have got side tracked with other more important stuff.  Life happens while you're making other plans, but I hope to have more time in the shop by mid January or so.

I got different carbs from you and Walt, mine came from a YZF600r Thundercat (Kehin 36mm), and have longish intake trumpets.  This takes up a bit more room than the shorter front carbs you guys have.  So I empathize with Walt's comment regarding the tight quarters for fitting these things.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 10, 2016, 01:46:35 PM
Mike,
I know what you mean. i had to take a long break on thi.s project my self.

I'm not familiar with the carbs you have. One thing that helped with the mikunis was to grind clearance for the rear float bowl in the head stay from the rear head to the frame to allow the carbs to sit lower, closer to the head. It's definitely a tight fit. Setting up the cable stops, linkage, and plumbing can take some patience, but it's worth it. It's like a whole new bike, much less finicky.
Best of luck,
    Ron

Title: Re: FZR carb conversion
Post by: Walt_M. on November 12, 2016, 02:24:22 PM
Ron, I just noticed you have a different fork on your bike. What is it and what is the offset of the triple clamps?
Title: Re: FZR carb conversion
Post by: fiat-doctor on November 13, 2016, 10:39:18 AM
Great work both of you!  I just wanted to say what a great inspiration you are to all of us and also by sharing the info on jetting, that you have learned along the way you have made the job that much easier for those who follow your path. Steve
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 15, 2016, 11:28:17 PM
Walt, the forks are from a Kawasaki ZZR1200. The offset is 2.30 inches center of steering stem to tube centerline.
Title: Re: FZR carb conversion
Post by: fret not on November 16, 2016, 12:41:33 AM
Looking good, Ron.  Did you have any clearance issues with banging into the radiator or tank?
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 16, 2016, 01:31:18 PM
Mike, had to make my own steering stops anyway so no problems with hitting tank or radiator. It has plenty of turning lock.
Title: Re: FZR carb conversion
Post by: fret not on November 17, 2016, 01:28:45 AM
That's good to know.  How do you like the handling with the 'new' front end?
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 19, 2016, 12:01:07 PM
  The handling is much improved. All the flex and twisting of the stock forks is gone, or at least reduced so much it's no longer noticeable. I live in the mountains so most of my riding is on twisty roads. A few years ago I had two Visions, one with stock forks and this one so I've had opportunity for comparison. I was going to leave the stocker stock, but ended up changing the forks on it too. The improvement was too good to pass up. I was commuting about 110 miles a day on a mixture of mountain roads and freeway.
  The reason I had to fab my own fork stops was that I only got the fork legs without clamps and had to fab my own triple clamps. It would probably be just great luck to find forks that worked with the stock fork stops without modification or fabrication.
Title: Re: FZR carb conversion
Post by: fret not on November 20, 2016, 01:17:41 AM
Fabricated your own triple clamps!  OK, so you are a machinist then.  Did you calculate for trail or not?  I know there is some geometry that needs to be respected when working with the front end.

I have a set of '87 FZR 1000 forks I would like to use but the triple clamps don't have enough set back for the stem.  The legs would bang into the radiator shroud and probably the tank.  I know stops must be fabricated so that's not a huge problem.  I tried installing them last year but lock to lock reminded me of my old road racers with very limited steering, and that was without stops yet. Triple clamps, yet another project to add to the list.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 21, 2016, 08:42:57 PM
  Not only calculated for trail, but experimented with eccentric bushings, stem into triple clamps, to get it where I like it best. A little more offset on the top triple clamp than the bottom gives more steering lock. That also allows more trail with more offset which is what gives more lock.  Trail is just under four inches. The last forks I had on the Vision started out at the stock 4.5 inches of trail, but as I brought it down some the tendency to oscillate on turn in went away and stability remained excellent.
Title: Re: FZR carb conversion
Post by: fret not on November 22, 2016, 12:37:59 AM
So what is the difference between the stock triple clamps and the new ones you made?  I mean how much difference in off set from stock.

This may well bruise my thinking muscle before I'm done.  It's old and not well developed.
Title: Re: FZR carb conversion
Post by: Rikugun on November 22, 2016, 06:49:09 AM
I had PM'd Ron about this but some of these details are new - like the eccentric Bush theory. And no, that's not a political jab.   ;) If you look at the top triple you can see weld joints where the larger tubes have been accommodated by a welded on clamp section. Ron can correct me but it seems the offset (at least on the top clamp) is very Vision-like.
Title: Re: FZR carb conversion
Post by: fret not on December 04, 2016, 12:44:46 AM
It would be nice to see a pic or two.  I'm trying to mentally formulate a design and process to end with a good set of triple clamps.  My first thought is to cut them out of aluminum billet.

Is the stem threaded into the lower clamp or is it pressed into place?
Title: Re: FZR carb conversion
Post by: Walt_M. on February 01, 2017, 03:57:24 PM
Thanks to Ron for the relocation. We should start a new thread on the fork offset.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on May 17, 2017, 02:40:14 PM
Sorry to be so long in replying, but I finally found my notes from 1985 when I did the fork swap. The top clamp is offset 2.30 inches center of steering stem to center of fork tubes. The bottom clamp offset is 2.20 inches. These offsets were arrived at by fabbing a set with oversized holes for the steering stem and pressing in bushings with offset bores to change fork offset. That way I could experiment with offset and trail without having to machine a whole new set of triple clamps for each change. It took a while and a lot of work to get it where I wanted it, but the bike handles really well with great front end feel and feed back.
Back to the carburetor swap. It was running really well, but I found that on really long uphill pulls, several miles, it was surging and losing power like it was running out of gas. Checking out the FZR specs, seeing that it ran an electric fuel pump and noting that Walt M is running an electric fuel pump, I ordered an FZR pump. Problem cured. It really runs great now everywhere. Starts even better than the huge improvement before the new fuel pump.



Title: Re: FZR carb conversion
Post by: Rikugun on May 18, 2017, 10:26:37 AM
Good stuff there - thanks for the updates Ron. I like the solution of having replaceable bushings to experiment with offsets.
Title: Re: FZR carb conversion
Post by: cvincer on May 24, 2017, 09:49:30 AM


Tried to view the   Walt_M   July 01   2016    photos of his FZR carb conversion but always got:-

           404   Attachment Not Found

Does anyone know how to view old photo attachments   (& 2016 isn't really so long ago)

Thanks

Title: Re: FZR carb conversion
Post by: Walt_M. on May 24, 2017, 06:49:09 PM
I will try to locate them and repost.
Title: Re: FZR carb conversion
Post by: Jirik on May 26, 2017, 07:41:01 AM
I have the same problem with attachments as cvincer, but in WHOLE forum. I can't see any photos, nothing :'( :'( :'(
Title: Re: FZR carb conversion
Post by: Walt_M. on May 26, 2017, 08:33:27 AM
This looks like a job for Ron. I can't even repost the photos. I get an error,  can not access path for upload.
Title: Re: FZR carb conversion
Post by: turbosteve84 on May 26, 2017, 01:39:20 PM
I don't know if this is helpful or not, but you need to be logged in to view images. You can read the posts WITHOUT being logged in, but you won't be able to view the images. At least that's been my experience.

--Steve
Title: Re: FZR carb conversion
Post by: Prophet Of Doom on May 26, 2017, 05:07:24 PM
Pics are all gone.  Can't post new ones either.  I emailed Ron yesterday, but no reply yet

Title: Re: FZR carb conversion
Post by: fret not on May 29, 2017, 11:56:08 PM
Ron McCoy, I just re-read some of your postings and have come to the conclusion that you might have been commuting to the JPL facility all this time.  You are a bit more than thorough in your R&D process, and certainly more thorough than 99% of the bike riders I know, and I know some decent fabricators.  I tip my hat to you.  Thanks for the information and insight.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on June 05, 2017, 07:48:25 PM
Thanks Mike, but never worked for JPL though I have done work for Lawrence Livermore Laboratories and Northrop at a large machine/fabrication shop I worked for. I learned most of my methods from my dad, a really good mechanic who also built engines and speed equipment for dirt track midgets back in the V-8 60 days. Quite an education. After my tour with Uncle Sam, I worked as a welder/fabricator, machinist, industrial maintenance tech/manager, and engineering project manager so I learned a lot of skills that come in handy for building hot rods and motorcycles and even bicycles.
Title: Re: FZR carb conversion
Post by: fret not on June 07, 2017, 03:42:07 AM
Wow!   Very interesting career path.  Do you have a wizard hat? ;)
Title: Re: FZR carb conversion
Post by: Ron_McCoy on June 07, 2017, 11:04:38 PM
Can't be afraid to jump in and try something outside your comfort zone. Great to be retired though.
Title: Re: FZR carb conversion
Post by: artbone on July 03, 2017, 04:53:26 PM
I want to do this mod on my 82 which I'll have here before the end of the year. I was looking at V Max carbs but you guys have done so much work with such good results I don't think I want to reinvent the wheel. I'm checking carbs on ebay and the prices are all over the place but it looks like I can get a set for about $100 so that's cheap enough. Would you post a sketch of what the carb to manifold adopters look like and the dimensions?
Title: Re: FZR carb conversion
Post by: Walt_M. on July 03, 2017, 06:51:09 PM
You already have what the carb to manifold adapter looks like. Make it look like your stock carb spigot and about 50 to 60 mm long. You can't use Vmax carbs straight to the manifold because there isn't enough room in the V.
Title: Re: FZR carb conversion
Post by: artbone on July 03, 2017, 07:08:39 PM
You already have what the carb to manifold adapter looks like. Make it look like your stock carb spigot and about 50 to 60 mm long. You can't use Vmax carbs straight to the manifold because there isn't enough room in the V.

That's what I thought. You guys have made this so much easier though how much easier is still to be seen. Thanks for your good work.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on November 25, 2017, 01:04:43 AM
Just a follow up on this project. I have just over five thousand miles on it since the installation. It starts easily and quickly. Now that winter type weather has arrived, it likes a little warm up before it will accept much throttle so the jetting is pretty close. Getting 50 - 55 mpg with really good throttle response, no stumble or hesitation. Yamaha should have built them this way to begin with. Itís a much more enjoyable motorcycle.
Title: Re: FZR carb conversion
Post by: jefferson on November 25, 2017, 04:32:35 PM
The vmax carbs do fit right up to the manifolds according to my friend that has done it. They just need to be spread apart more in order to line up. He has that setup on the bike now. The accelerator pump nozzle fell out of one of the stock carbs and went through to the combustion chamber. He got some of the timing off somewhere during the teardown and reassembly and it looks like he may have bent some valves. It was kind of surprising, but there was no visible marks from the nozzle rattling around in there. Sure flattened it out though.
Title: Re: FZR carb conversion
Post by: Walt_M. on November 26, 2017, 03:16:59 AM
I went back to the beginning of this thread and will modify my statement that vmax carbs will not fit straight to the manifold and be linked together.
Title: Re: FZR carb conversion
Post by: auto on November 26, 2017, 08:02:35 AM
Anyone have two vmax carbs they want to sell.Like to try a conversion but don't want to buy four carbs.Also looking for a trashed out exhaust that I can open up to explore best way to improve flow,but not too loud.
Title: Re: FZR carb conversion
Post by: Walt_M. on November 26, 2017, 10:43:55 AM
People are pretty brave on pricing Vmax carbs while I have found FZR600 carbs around $100-125. And, as I found out, the first and third carbs were best for my purposes. Another benefit of this conversion, since I no longer have the airbox flapper, I have hardly any oil in the airbox from the crankcase vent, which makes perfect sense when you think about it
Title: Re: FZR carb conversion
Post by: fret not on November 29, 2017, 03:32:04 AM
While looking through the various offerings of carburetors on eBay I have found terminology is often misused.  The term "carbs" or carburetors is all too often used when trying to sell throttle bodies for fuel injection.  You have to look closely at the photos, and if things aren't clear then ask a question of the seller to establish clarity. 

A couple years ago I bought a set of throttle bodies from a Suzuki SV650, thinking I would graft them onto my Vision.  After some serious brain sweat I came to the conclusion that grafting carburetors on to the Vision would be a smaller mountain to climb.  In the process I got an introduction to fuel injection, and the difference between the fuel systems.  FI requires rather high fuel pressure, about 42psi as a minimum, and consequently all the fuel line fittings are designed to deal with such pressure.  FI may look simpler at first glance but in reality carbs are easier.

Throttle bodies seem to be much less expensive than carbs.  My guess is they seldom need work or replacement so not much market for them.  Carbs on the other hand seem to sell more easily and so maintain their market value.
Title: Re: FZR carb conversion
Post by: Kenny on December 12, 2017, 12:33:25 AM
    All right ...
    I'm into the conversion mode - I've got a set off of a 93 on the way ! I must say I'm a bit ticked with the 83 carbs I've reworked over and over , I can get them to work o.k. but after a year or so I need to do them again . Earlier in the scheme of things I sent a set of 83 Canadian Carbs to Martin at S.C.I. and he sent them over to Japan & they made a carb kit up for the 83 as the only one they had was for the 82. After that I overhauled all the carbs I had -did them up in an Ultra-Sonic Cleaner at work until they pretty much Glowed in the dark ! But after a couple of years of use , (even with an inline filter installed) I was back to reworking them again. Geez I hope I'm not repeating myself here..
   Can't wait to get started , I'm calling this a Christmas Gift.
                            Cheers Kenny         
Title: Re: FZR carb conversion
Post by: fret not on December 12, 2017, 03:37:40 AM
Well, good luck with the process.  You just have to keep in mind that there is less troublesome performance at the end of the journey.
Title: Re: FZR carb conversion
Post by: Rikugun on December 12, 2017, 12:56:21 PM
I can tell this is a sore subject to ask about and I'm not trying to talk you out of the conversion, but....   :)

I'm curious as to why the carbs had to be reworked so often. You specifically mentioned running an inline filter which has be wondering if you found debris in the bowls at each rebuild? Is your tank suspect? If so, wouldn't the new carbs be vulnerable too?
Title: Re: FZR carb conversion
Post by: jefferson on December 12, 2017, 02:40:01 PM
I'm betting on ethanol in the fuel and yes it would affect the new carbs as well.
Title: Re: FZR carb conversion
Post by: Walt_M. on December 12, 2017, 03:48:21 PM
I got ethanol resistant neoprene, viton, gaskets for mine and the carb floats are nylon so no problem there but I still avoid ethanol. That stuff is just nasty.
Title: Re: FZR carb conversion
Post by: Kenny on December 14, 2017, 03:02:22 PM
      I was running three 83 visions one yellow /red along with two red and whites.  All the tanks were lined with Caswell and had no loose or free particles. No particles in the filter and I was using a Uni Filter in all three. I was using one the high mileage (110,000kms) R/W machine that was done up with a Fox single Clicker , Euro gears and whit Krauser Bags for my cross Canada runs in the fall . The Carbs on this bike worked fine and for the most part I used Premium fuel, I was running around 12,000kms on each trip. The other two my wife rode on occasion and I rode them to work as well.
   During this time and over the years I was forever fiddling and overhauling the carbs and the stumble would come and go. I don't have access to an Ultras Sonic machine (retirement) and just want an easier go.
       Cheers Kenny     
Title: Re: FZR carb conversion
Post by: Rikugun on December 16, 2017, 06:45:33 PM
Gotcha, thanks for the clarification!
Title: Re: FZR carb conversion
Post by: fret not on January 09, 2018, 10:56:30 AM
Ron McCoy, what thickness of aluminum plate did you use for your triple clamps?  I have access to some free 1" stock, but maybe it would be better to use 1 1/4" or 1 1/2"stock. (6061 t651)
Title: Re: FZR carb conversion
Post by: Ron_McCoy on January 09, 2018, 11:12:44 PM
Mike, I made my lower triple clamp and tube clamps for the upper triple clamp from 1Ē 6061 T6 plate.  I used it for the same reason youíre thinking of, it was available and free. They seem more than rigid enough and clamp the stanchions very securely. The lateral stiffness of the fork assembly is a terrific improvement.
Title: Re: FZR carb conversion
Post by: fret not on January 10, 2018, 03:12:19 AM
Thank you Ron.  Big help.
Title: Re: FZR carb conversion
Post by: Ron_McCoy on January 11, 2018, 12:33:17 AM
Youíre welcome Mike. Glad if I can help. Best of luck with your projects.
Title: Re: FZR carb conversion
Post by: fret not on September 15, 2018, 01:42:34 AM
I have a question that may well have been answered previously, but if so I am not aware of it.  The question is: have you fellows with the FZR carbs had any issues from running them with the bores straight up rather than at the angle they were mounted in their original application?  The reason I ask is the float bowl fuel level is a bit different at the two different angles, and that could probably cause some tuning and or fuel starvation issues at times.  Or, . . . is that not a problem?

I have gone to the lengths of making sure my carbs are mounted at the original use angle.  Now I am wondering if I have wasted time and effort to accomplish that.  It would be soooooo much easier to just plug them straight into the rubber boots.  Also, my 'design' has a bit longer intake tract as a result.  I have no idea if that is a good or bad thing.  If it works it is a good thing.
Title: Re: FZR carb conversion
Post by: Walt_M. on September 15, 2018, 07:59:37 AM
I haven't had any problems that I could relate to float level.
Title: Re: FZR carb conversion
Post by: fret not on September 15, 2018, 12:50:40 PM
That is my point, and thanks Walt.
Title: Re: FZR carb conversion
Post by: fret not on September 18, 2018, 03:38:14 AM
If the carbs are not negatively effected by standing them straight up then the original air box (as YOU point out) should not need much if any modifications.  With the carbs from the YZF600r that I am using I chose the pair that has the bell crank and left them connected together as they were in their original application.  This caused me to make up new manifolds to fit the carbs.  It is MUCH easier to use original manifolds than it is to make new ones, but I didn't have to fabricate linkages and such between the carbs.  Since I have a spare air box I will modify one to accommodate the "new" carbs. 
Title: Re: FZR carb conversion
Post by: injuhneer on July 01, 2019, 10:58:46 AM
People are pretty brave on pricing Vmax carbs while I have found FZR600 carbs around $100-125. And, as I found out, the first and third carbs were best for my purposes. Another benefit of this conversion, since I no longer have the airbox flapper, I have hardly any oil in the airbox from the crankcase vent, which makes perfect sense when you think about it

You can buy a rack of (V4) Venture carbs for a lot less than VMax carbs. They are nearly identical. VMax folks use the Venture carb bodies as spares.
Here is a thread:

http://ridersofvision.net/rovforum/index.php?topic=15881.0


Now I am wondering if a 2 cylinder version of V-Boost would work...
Title: Re: FZR carb conversion
Post by: livetoride21 on April 16, 2020, 10:22:06 PM
Just read through this whole thread, nice work!
I just picked up an first year Vision 550 and will be building a vintage race bike out of it.
The FCR carb conversion is very attactive for me because I already have a rack in stock!
Curious, what jetting did you end up at? I saw 32.5 pilot, 127.5 main, and 52.5 starter, is that correct? Did you ever do a plug chop?

thanks!
Hope you're still here on the forum.

Kevin
Title: Re: FZR carb conversion
Post by: fret not on April 17, 2020, 03:39:09 AM
I just left the jets that were in the FCR carbs in place as they should be within the ball park if they are stock, which I believe they are.  Hopefully this will be a good starting point for fine tuning.  Also, it may be some time before I actually run the bike to find out as there are some other areas that need attention before that can happen.
Title: Re: FZR carb conversion
Post by: livetoride21 on April 17, 2020, 06:37:10 PM
Thanks for the reply back Fret not.
I actually slipped up and had FCR on my mind, but meant to write "FZR" as in the FZR600 carburetors.
Hoping Walt can shed some light on it.

Title: Re: FZR carb conversion
Post by: Walt_M. on April 18, 2020, 07:07:25 AM
Yes, that's where I left the jetting. I never did do a plug chop as it ran pretty good there. Just a thought if you're thinking of track time, I believe it lost some power on top due to the smaller bore. but it could be the jetting.
Title: Re: FZR carb conversion
Post by: livetoride21 on April 18, 2020, 09:01:11 PM
Thanks for the reply Walt! I'll try it out. I have them in stock, so it be worth while to test.
Will try it out with your jetting and see what it nets. As far as losing power on top, I wonder how much air these motors can really pump through 34mm bore? I mean I have-to figure if two 41mm are enough to feed my 944cc ducati, two 34mm carbs should be adequate to feed the 550 up top.
Have you ever tried YZF600 (thundercat) carbs? I believe they're slightly larger bore, but very similar.
Title: Re: FZR carb conversion
Post by: fret not on April 19, 2020, 10:54:21 PM
Yes, that is what I have.  From a YZF600R Thunder Cat.  Made by Kehin, and they have nice long trumpets.  As I recall, Tree Dragon said he put another set of the rubber boots in the airbox to lengthen that intake and smooth the air.  He reported it made a noticeable difference.  I miss his participation here, he had some good "tales" to tell about his marvelously developed bike.
Title: Re: FZR carb conversion
Post by: livetoride21 on April 20, 2020, 08:28:57 AM
Interesting, for some reason I thought you had put fcrs ( flat slide non cv carbs)
Thanks for the reply, you said youre running the stock thundercat jetting?
Title: Re: FZR carb conversion
Post by: fret not on April 21, 2020, 12:45:24 AM
Not running yet, still in the "project" stage.