It was a longer project for the guys at Factory Pro to get this worked out BUT it is done!
My 1983 Vision no longer has the stock carburetors. It is now using a single down draft carburetor. The mechanics told me the top speed may no longer be 105 MPH (I know, the specs say 113. I bought a brand new 1983, in 1983 and I could not get it past the 105 on the speedometer). I just got the bike back a couple of days ago and only had time for a quick test ride going home. On that ride, 75 MPH was the fastest I went (no sure what top end is yet). I guess anyone interested in this modification would have to ask themselves, what is the fasted I have ridden the bike in the last year or two and is that 100 MPH something they really need or could you live without that to have a bike that does what you want it to do when you want it done without any quirks or idiosyncrasies.
I was in my thirty's when I need to see how fast the bike could go, now I'm not in as big of a hurry to get to the end of the line anymore.
Along with giving up some top end, you'll also give up al;l those things you hate about the bike! The carburetors that everyone likes to say just need a little cleaning or adjustment or whatever they use for their excuse as to way the bike doesn't run properly. You will also lose the stock air cleaner, the Airbox and all of it non adjustable variables.
What you will gain is a bike that starts right up cold or hot. A bike that does NOT have a stumble or a lag when you twist the throttle. You will also have parts that are available to keep it running like this for years to come.
I had put up a post on this back in May 2013 but being the conversion took longer that expected the info for a kit was never worked out at that time but the mechanics had estimated it would be about $1,500.00. They are now trying to get that all worked out so that a complete ready to install kit could be purchased.
I will do a follow up post as soon as I have that information. I will also try to get a video made so that you would be able to hear it on the road..
Sounds interesting, but if you don't post pics and juicy details (like the type of carb) then it didn't happen.
A lot of variables in that top speed thing, but it would still be interesting to see how it does now. Keep some tabs on your mileage and let us know how that works out.
Kudos on a job well done. A modification of this sort is rare as much as for the work involved, but also the cost. Quite some dedication there.
Jeff
Is it still a downdraught type carby?
Very cool. Want to sell your '83 carbs?
I'll have two sets of 83s and an 82 set for sale. Would you be interested in an air box also? Make me a reasonable offer and it can all be yours. wayneweb22@hot mail.com
Factory speedo accuracy may be suspect. Better indicator is what is max rpm available in top gear. My '83 has red lined 5th gear more than once. Each time it was showing 114mph.
It sounds like a compromise and one you are willing to live with so that's all that counts. :) Depending on how the bike is used I can see where the positives may out weigh the negative. Please keep us updated with riding impression feedback and some pics and details too.
On the reduced power thing... I rarely operate at the ton but it's more than top speed - it's the HP required to get there. Just this weekend I was following my friend on his Tiger Explorer (130+ HP) on one of his "hooligan" rides through the back roads. He was being kind to me but still he was using moderate throttle and maybe 2 gears where I was working the Vision hard through several gears to keep pace. My new braking components got a thorough work-out too BTW. My brother was behind me on his 800 Tiger and later told me he just "used a gear lower than normal" to maintain the pace. If it had been me back there, it would have been much more work to keep up as there seems to be an exponential factor for each position back you are. :)
I don't feel the need to go 100 often but don't like the idea of giving up the HP that makes it possible. Just my 2 cents... :)
The way it looks now. Will supply a video soon (days, not minutes). There are still people that don't believe a tree falling in the forest makes noise if they don't hear it! Listen up.
If there is no eardrum to convert the sound waves into perceived noise then maybe not
This is a good time for a name change. Single downdraft slide carburetor. Went to take my daughter to school this morning and after I dropped her off and returned home I figured I'd see how the bike is starting today being the temperature got a little cool last night. The bike has been parked in the street for the last several days. It was 42 degrees out this morning. I pulled out the choke, turned the key to on and pushed the start button. The engine fired immediately, it didn't even have time to go r r, r r. It just started, period, done, ready to go.
A little horse power info I do have. If I remember what I was told correctly, (I didn't write it down) the dyno horse power showed 45 HP, but that is at the rear wheel. The mechanics at Factory Pro said that the rear wheel horse power is figured at about 20% less than crank horse power. I think the Vision specs show the bike as having 60 HP but that is at the crank. So if you take 20% off of 60 you will get 48 HP at the rear wheel. Figuring things out in reverse to have 45 HP at the rear wheel, you would have 56 HP at the crank. If all those numbers are 100% correct (and they can't be as we have an @20% in there) then the bike would have 4 less HP than stock. While we are down to splitting hairs, I guess we should also consider that we lost the weight of the stock carburetors and the air box. I'll work on getting more info and a video.
So, what kind of carb is the new single carb kit? Mikuni, DelLorto, Amal, Weber, SU, ?
Mikuni is what they ended up with.
Pullshocks had asked if I would sell the 83 carbs. I replied to him make an offer. He has not replied yet. I have two sets of 83s (one set of the 83s has a bracket or some other small external part missing but the other set has it and if you already have carbs, you already have it also.) I also have a set for an 82. All are for sale along with air box. Make a reasonable offer, plus shipping and pay me with paypal and they will be on the way to you. Thanks.
Have you noticed an increase in torque at lower revs? I'm pretty interested in this, could you please provide more details?
Venturi size of the new carb?
I don't have all of the specifics of the new carbs. I do know it had to be reworked as it wasn't something that just came out of the box and all was good. Once they decided on a carb that would fit the bike without having to change the look they then spent weeks/ maybe months getting it where it is now. I can't give you any torque info right now. The bike ran like crap when I got it and I didn't feel safe riding it as it was like some other guy said you had to give it gas very s l o o o w w or it would just cough and die. I like to know that when I twist the throttle, I'm going right now. That is the way it runs now, there is never any lag or stumble. I do know that I left a stop sign a little quicker than I actually planned on leaving and the front wheel was suddenly not in contact with the ground any longer. All I can say right now is that as soon as the guys at Factory Pro get a complete kit all worked out including price, I'll post the info.
Excuse me, I meant to say new carb (singular ). I guess I'll have to get used to that.
Are your Factory Pro guys the same ones who wrote about finding casting sand in the vision carbs?
http://www.factorypro.com/prod_pages/prodyXZ550.htm (http://www.factorypro.com/prod_pages/prodyXZ550.htm)
Yes, they are all in the same shop. The guys that took on this carbureator project were not involved in the early racing days of the Vision but the guy that found that sand problem mostly runs the dyno part of the business now.
Bike has been sitting in my unattached, unheated garage for over a month now. It was 31 degrees outside this morning so I thought this would be a good time to again test cold weather starting. Choke out, key on, one very shout rr and it came to life and continued to run. Cold weather starting is not going to be a problem with the new carb set up. That's all the news for now.
You have the solution on hand which I posted years ago. '83 carbs w '82 pilot jets and accelerator pump at max stroke. My '83 ran awesome w those mods. My AC Vision which runs great has very similar carbs-downdrafters unlike the larger Viragos w sidewinders that lots of guys put single carbs on. I also had an XV920R that ran good too-especially after I built a custom 2-1-2 exhaust for it(stock was worse than standard Vision system). Carb stuff is detail intensive-miss one little leak one obstruction and you're screwed. If I sound crabby EXCUSE ME!! I just plowed the 1st big snow from my drive after working on Daughter's Jeep-oil,coolant,block heater,serpentine belt. GJ ::)
Like an old friend of mine would always ask while things weren't going so great, "are we having fun yet?"
Soooo?? When do we get to see what you got? You have piqued some interest among the 'crew', and now we want more information, pics, names, numbers, etc.
Bump ??? Whatcha got?
Finally took the bike out for a ride, it's been sitting for a long time while I was mounting a rack rear box and also putting on a small sissy bar/back rest for my daughter. I was on some country style back roads. The bike had no trouble hitting 85 MPH and I only brought it up to 8500 RPM (not both of those at the same time). About 6500 RPM at 85 MPH on the freeway heading back home in commute traffic. Refilled with gas at end of ride, millage was 40 MPG after an 80 mile ride. No hesitations no stumbles not one glitch of any kind.. It almost made me forget to act my age. I'm a happy camper with the single carb conversion.
So, after more than a year since your announcement we get what? " . .but wait, there's more". Are these guys going to offer carb 'kits' or not? And if so, how much $ ?
I've asked them about kits a couple of times and they say they'll have to see what they can put together. It doesn't seem like they want to pursue that plan. I'll ask them about it one more time and if I get some news I'll let you know. Maybe the good news is just that we (I) now know it can be done for anyone that wants to work at it. Remember they had my bike for a long time before they were able to put together something that worked. I know there was a lot more to it than just getting a manifold, carb, air cleaner and throttle cable. If I get news, you'll get news.
It doesn't sound like Factory Pro will be making any kits. At the guestimated $1500 dollar price tag I doubt they'd sell enough to warrant the development time.
So what we know so far it's a Mikuni slide throttle of unknown size. Back in 2013 you referred to it as "Single downdraft slide carburetor". Is this accurate? All slide throttle carbs I've seen are side draft. A picture or two would go a long way to satisfying some of the group's curiosity. Without having to remove the fairing lowers or tank can't a pic be had that would show something?
Who were some of the guys you worked with at Factory Pro? Maybe a name and email addy would be useful for someone to make queries directly to them.
Well, $1500. usd is a bit more than my "account" will allow, especially if there is a decrease in performance. I can make my own manifold if necessary, especially since seeing those youtube "King of Random" videos.
Exactly. I agree the price is prohibitive although the performance loss doesn't appear to be as dramatic as I first thought. I thought if more specifics could be learned about the carb model & venturi size, jet sizes, etc. some may consider taking on the project themselves.
Obviously it takes some fabricating skills and cost but may be an attractive project for some. I'd think better overall fueling and significantly simpler carb design are worthwhile features although 40MPG seems a bit low for a Vision. In fairness the OP describes a riding style that may account for some of that.
Have you done any tuning to the carb yet, or is it running as you bolted it on? Reason I ask, if i have a couple 34mm round slide mikunis off a 600cc snowmobile, and i'm curious how "in the ballpark" it might be. Made fairly simply adaptors to use the stock carb mounts. For the price of a couple carbs and some throttle cable, if i can get the tune down "close enough" it'd be another easy conversion for others. Once i swap the base cylinder gaskets on my motor, i'm hoping to attempt to start it up again.
Blake
I have not touched it at all. The shop where I had the work done tried at least a couple of other carbs before the one on the bike now. They had to make modifications to the carb and they had their dyno to tweak the carb as needed to get the best results they could. I also don't have any idea what changes they may have made to the YICS. Hope your plan works out. If you have parts to experiment with you have nothing to lose but some time. I'm sure Ive seen some pictures or postings somewhere of other people switching to a one carb system. I was kind of surprised to see that after thirty years of problems more people haven't tried it. Good luck and if I do get more information to pass on to you, I will.
While the notion seems very simple in practice the swap is more complicated than it seems. Even the shop you tasked with the job seemed to be stumped for a while and this is their business. I'm not sure how much you have invested but I'd imagine it's more than some have paid for their Vision.
Without professional help and unless you get lucky, stumbling upon just the right carb setup on the first try seems unlikely. Without the use of a dyno and especially exhaust analyzer, could result in many, many long hours of fruitless trial and error. That may be why more haven't tried it. Just my 2 cents. ;)
Quote from: Rikugun on March 28, 2015, 08:24:44 PM
unless you get lucky, stumbling upon just the right carb setup on the first try seems unlikely.
A double word play. Nice!!!
Seems to me if you have the gear and skills to make a different carb work, then you have the gear and skills to make the original carb work again. Unless you particularly want to do a swap it seems all a bit pointless.
Stumbling... yeah was that intentional? I agree with POD on this one, summed it up well.
Yes it was intentional but I felt a little bad for going for such low hanging fruit :)
Also agree with the idea of skills utilized to get the OEM carbs right although some may just enjoy the project for it's own sake. Whatever gets your Vision functional and out on the road is good by me!
I agree with whatever it takes to get it running properly. It seems clear that these carburetors have been a problem for thirty years. There are parts on carburetors that wear out, ( I used to do all of the work on my own cars and bikes when I was younger. I had many friends that were in to drag racing and NEVER did a rebuilt carburetor work as well as a new one ) there are shafts and pivot points that can't be replaced. Top that off with the fact that many of the replaceable parts for these Vision carburetors are no longer available. If you can find something NEW, that you can get to fit in the allowed area and only have to do some jetting then that's a good reason to replace them because you will also be able to get new parts for a current model.
Add to the mix the YICS and the airbox, with it own air damper and your going to be fighting a never ending battle, as shown by thirty years of problems.
About two years ago (while the work was being done on my bike ) I saw an 83 for sale on e bay. From all of the pictures it looked like brand new as it should have, it only had around 3,500 miles on it. I thought it might be a good idea for me to buy it because of the excellent condition. If I remember correctly the guy was asking $5,000.00 for it. High price but it was immaculate!
Then there it was at the bottom of the add "just needs some minor carburetor work". That was all I needed to see to end my interest. It never got to the reserve has been met point and I didn't see it listed again.
I see your points and understand completely the route you chose.
Regarding used bike adds (Visions particularly) stating "just needs minor carb work" - add this statement to the list.... "the check is in the mail" and "I'll respect you in the morning". ;D
Quote from: Rikugun on March 31, 2015, 10:38:10 AM
I see your points and understand completely the route you chose.
Regarding used bike adds (Visions particularly) stating "just needs minor carb work" - add this statement to the list.... "the check is in the mail" and "I'll respect you in the morning". ;D
That's for sure. Remember that black 400 I worked on last year? That was sold as works well - just has a flat battery. I put 2 months of labour into that and $1000 worth of parts and it was still giving problems.
This thread started in November 2013 ...... any photos yet?
Quote from: cvincer on April 22, 2015, 01:58:42 AM
This thread started in November 2013 ...... any photos yet?
Nah it's all BS
Maybe a real dual throat Weber would be a better answer. Didn't John Clemmons put one on his racer?
I've got a dual throat weber - it was on Glynn's bike and I liberated it.
Haven't decided to use that or to beat my stock ones into submission
Perhaps Treedragon (New Zealand) with his dual throat off a Ducati & that chap in Europe using a
Dell O'rto are the only ones.
Glynn's Vision was his daily rider. He was very pleased with the Weber - the only reason I ended up with it is that he sold his bike to Iain down the road and I talked Iain out of it. I'm still working on getting the rest of the bike :-) There are picture of the conversion somewhere on this site.
Treedragon is not riding last I heard following an incident with a dyno.
.......... that's a shame, his exploits with the XZ were very interesting. Viewing his website displaying his artwork shows he had considerable talent in other areas also.
Quote from: cvincer on April 23, 2015, 07:21:30 AM
.......... that's a shame, his exploits with the XZ were very interesting. Viewing his website displaying his artwork shows he had considerable talent in other areas also.
Agreed. I hope all is well with Martin.
Martin sounded healthy enough - it's his vision that's seized. It wasn't even him on it at the time.
Oh. Well that's not good either. :(
Yep I think the best mod I ever made to my bike was to put an IDF weber carb onto it. Easy to tune and good materials. Getting the manifold welded up was the largest expense. Still when you add up the cost of keeping cleaning the stock carbs it makes alot of sense however.