Hey guys,
Just in the middle of rebuilding my first set of carbs and stumbled across something I find strange. This is going to be tough to explain without pics but I'm on my iPod. Looking down from the top of the carbs there are three passageways cast into the large cylinder part of each carb. The biggest of these contains a brass screw (pilot air jet? - I'm not sure what everything is called yet). My question lies in one of the smaller adjacent passages. As I look down one in one carb, it looks like there is a little brass ball blocking it. However, on the other carb there is nothing. This doesn't seem right to me. Is this a problem and if so, how should I go about solving it? I'll try to post some pics later. Thanks in advance for the help.
QuoteThis doesn't seem right to me
When it comes to theses carbs, when something seems wrong, it's probably the way it's supposed to be! ??? :D
I'm kidding of course (sorta) but it seems like what your describing is exactly as it should be. I think it's the front carb that has the ball bearing. It vents through the little filter attached to that carb with a short hose instead.
Heres some pics:
(http://i672.photobucket.com/albums/vv86/alanreintjes/Motorcycle%20Project/IMG_9752.jpg)
This is what I'm assuming is normal (in the smallest hole)
And here's the other carb:
(http://i672.photobucket.com/albums/vv86/alanreintjes/Motorcycle%20Project/IMG_9753.jpg)
Nope, that's correct. it is the way it should be.
that passage provides air to the main jet (called a 'bleed')
you have the updated version of the 82 carbs. On that version the front bleed has been blocked off, & rerouted to that little black & grey round disk on the front right of the carb. that disk is a filter.
basicly, what they have done is decided to feed air for that bleed from outside the airbox instead of thru the airbox filter. the reason is that with the flapper update, it cause undesirable effects on the air bleed due to pressure changes.
Quote from: Rikugun on September 26, 2010, 03:18:13 PM
When it comes to theses carbs, when something seems wrong, it's probably the way it's supposed to be! ??? :D
Haha, I am coming to realize that! :)
Just posted some pics (ignore that the brass screw is missing in the carb in question - i took it out for cleaning)
So the ball bearing is supposed to be there in one, and not the other as shown? Should I have tried to remove it for cleaning? I'm not sure how I'd ever be able to haha.
nope, leave it alone, it doesn't come out.
Quote from: Lucky on September 26, 2010, 03:18:47 PM
Nope, that's correct. it is the way it should be.
that passage provides air to the main jet (called a 'bleed')
you have the updated version of the 82 carbs. On that version the front bleed has been blocked off, & rerouted to that little black & grey round disk on the front right of the carb. that disk is a filter.
basicly, what they have done is decided to feed air for that bleed from outside the airbox instead of thru the airbox filter. the reason is that with the flapper update, it cause undesirable effects on the air bleed due to pressure changes.
Great! Thanks so much guys...you're all a ton of help
Hey! i'm only 210 pounds of help...not a ton, lol
WRX - just curious, what number(s) are the jets?
whooooah buddy!210 pounds? seems like its time for a diet
just kidding , i weigh 270
Quote from: Rikugun on September 26, 2010, 03:32:09 PM
WRX - just curious, what number(s) are the jets?
Sorry but I didn't check. I know one is a 120...the other I didn't glance at.
I may have screwed up bad tonight while putting everything back together. I broke one of the small plastic inlets at the bottom of the carb while fitting a small tube onto it. No idea how I'm going to fix this one yet...the plastic was so brittle that it shattered into pieces so I don't think epoxy-ing it will work.
Quote from: 2002_wrx on October 03, 2010, 12:55:42 AM
I may have screwed up bad tonight while putting everything back together. I broke one of the small plastic inlets at the bottom of the carb while fitting a small tube onto it. No idea how I'm going to fix this one yet...the plastic was so brittle that it shattered into pieces so I don't think epoxying it will work.
:) Don't worry, your not the first one to do this :o ::). Been there, done that...and fixed it, several years ago ;).
I had an old, worn out front carb manifold and removed the thinner of the two brass spigots. Filed the broken plastic flat and then drilled in to it about 1/8" - 3/16". I then used epoxy to install the brass spigot...VOILA!!!
You can, more or less, use any type of tube as long as its gas proof to do this repair... 8)
8).......TIGER....... 8)
yeah, I'm going to try to rig something up today. I figure it's not too critical of a part.
Any tips for trying to start up the bike for the first time? Might have a go at it tonight but I'm unsure of what will happen.
Nah, it's not too critical...just diverts leaking gas safely away from the hot engine is all.
My tip is have a fire extinguisher handy! ;) :)
Well, got it all put together and had the first start up. It started up relatively easy, but I've got a few problems.
1) Fuel dripping out of the overflow tube. I'm assuming that this means there is too much fuel in the float bowls. While cleaning the carbs, I replaced the needle and seat valves...the new ones were the same size, but stuck up a bit farther, forcing the floats to rest at about a 20 degree angle from where they were supposed to be. To compensate, I bent the small tabs on the floats so that the floats rested level, as they were before. So...where did I screw up? haha
2) Bike started up pretty easy, but won't run well. Symptoms include a self sustaining but surging idle, (Will idle around 1300 rpm and surge up to 2200ish) and no power. Like it struggles to get to higher rpm...and seems like it will die if I give it more gas. Long story short - it sounds like its getting too much fuel. Can this be corrected by synchronizing the carbs? Is this related at all to the fuel dripping from the overflow. I kept everything as it was when I disassembled the carbs...at least to the best of my knowledge. It ran pretty well before I started all this; it just wouldn't start one day so I began the cleaning process. Why is it running so differently now?
Sorry for so many questions...this is a learning experience for me and I appreciate the help.
Measure from the bottom edge (outside tip of float)of the float to the carb top and it should be about 35mm, that is the ballpark anyway. If you're less than that your fuel level is too high. You can also use a clear tube (hold it vertical beside the carb) on your float bowl drains (do them one at a time), and actually measure how far the top of the fuel is from the carb top which should be about 22mm ballpark.
You can do the latter without taking them off again. Now, that is if you have not broken off all your plastic drains :(. It sounds like you have a set of Canadian carbs with the 120 pilot jets on top, as that was standard up here.
Quote from: Cdnlouie on October 05, 2010, 12:10:37 AM
Measure from the bottom edge (outside tip of float)of the float to the carb top and it should be about 35mm, that is the ballpark anyway. If you're less than that your fuel level is too high. You can also use a clear tube (hold it vertical beside the carb) on your float bowl drains (do them one at a time), and actually measure how far the top of the fuel is from the carb top which should be about 22mm ballpark.
You can do the latter without taking them off again. Now, that is if you have not broken off all your plastic drains :(. It sounds like you have a set of Canadian carbs with the 120 pilot jets on top, as that was standard up here.
Well, went out and messed around with the bike tonight. It's sporadic and I can't get it to behave consistently. Today it wouldn't stay idling by itself, and would alternate between reving like normal and running horribly. Most of the time it would run with some throttle, but if I gave it any it would bog down and almost die.
Tried checking the fuel level using a tube connected to the drain pipes. Not sure if this is right but I would let the bike run for a minute or so, attach the clear tube to the drain, hold it vertically and loosen the drain plug a bit so fuel would come into the line. I then measured this level from the carb gasket line. Once or twice it was right around 20mm, but more often than not it would be around 24-25 mm. Also, the rear carb level was often lower.
Are they both supposed to be at the same level? Is this associated with replacing the needle valves?
On a side note: when looking down the carbs from the top, the accelerator pump nozzles were spraying fuel in a good pattern when I twisted the throttle so I assume they're not clogged up anymore. This was when the bike wasn't running. However, when the bike was running poorly and I took off the tank to look, both nozzles would just sputter and not spray anything.
Anybody experience anything like this? I really have no idea what I'm doing haha :-\
Quote from: 2002_wrx on October 05, 2010, 11:26:56 PMOn a side note: when looking down the carbs from the top, the accelerator pump nozzles were spraying fuel in a good pattern when I twisted the throttle so I assume they're not clogged up anymore. This was when the bike wasn't running. However, when the bike was running poorly and I took off the tank to look, both nozzles would just sputter and not spray anything.
Anybody experience anything like this? I really have no idea what I'm doing haha :-\
If you're looking down the carb throats with the engine running and the airbox off, you are _not_ going to see visible fuel spurting from the accel pump nozzles in a straight line or fan pattern as you did when it was not running - the 30 inches or so of vacuum in those twin venturis is going to suck that go-juice right into the hole and vaporize it faster than you can see it. Wait, did you say you looked down the tubes with it running _after_ you checked them while not running and found the accel pump nozzles to be clean, or only _before_ you cleaned them out, while the bike was running poorly? Not that looking at them now with the engine running would show you anything, anyway, due to the effect of the abovementioned vacuum suction.
Before I cleaned the carbs, I took the airbox off and looked down the top of the carbs. When I twisted the throttle (bike not running), a stream of fuel came out of the front accelerator pump nozzle and not the back one. I assumed this was my problem since the bike was stalling out and not starting.
After cleaning - the bike sporadically ran normal(ish). While it was running like this, I took the airbox off to look and fuel would come out of both nozzles when the bike was off and throttle was twisted. However, the bike started running bad. When I took off the airbox to look again, I wouldn't see streams of fuel, only sputtering from the pump nozzles while the bike was off and throttle twisted.
The accelerator pumps really are only there to keep the bike from bogging down while you're moving and crack the throttle open more. They don't do anything while the bike is starting or idling, so if you can't keep a steady idle I wouldn't look at the accelerator pumps, it must be something else.
The fuel level in the float bowels should be the same on both, it sounds like you're pretty close, I can look up the exact spec in a bit if I remember. Whether you've got new or old needle valves doesn't matter, if it's at the wrong level it needs to be fixed.
You might need to clean the carb again. If it was running better just after you cleaned it the first time but it got worse it sounds to me like a bit of grime that was loosened w/ your first cleaning got out and is now clogging something up somewhere else.
Yeah, that's what I'm wondering...today it wouldn't start again so I'm thinking maybe something else got clogged up.
When I go to clean it round 2, what else should I do? I dipped the carbs in Yamalube carb cleaner and tried to get all the passages cleaned out by spraying carb cleaner thru and running copper wires and things thru. The only thing I didn't pull out were the emulsion tubes - I wasn't even sure if these could come out.
As for adjusting the floats, I'm assuming it will be easier to measure fuel level with the carbs taken apart. I couldn't really get consistent results measuring from the drains.
Also - probably a dumb question, but are spark plugs for a motorcycle the same size as a car? Couldn't get my socket to fit for some reason
Spark plugs, there are several sizes. Different socket for each size. Get one that fits. ;)
spec is 20mm from the gasket for the drain test, and 36mm from the gasket measuring the float height directly. both +- 1mm
For your 2nd round just do more of the same. It's not that you missed anything in your first dip, it's just the softening of the cleaner and the vibration of it being on a running bike again that breaks more bits off to clog up the works. I just dip, rinse, and spray out everything with compressed air.
:) Spark plug socket size for a Vision...
18mm 8).......TIGER....... 8)
Sticking wires into tiny carb passages is generally not a recomended procedure. Sticking compressed air in, is the recommended procedure. The emullsion tubes screw out. Yours are probably plugged. The float level is best set using the overflow drain spigot and clear tubing process with the fuel petcock set on prime.
Quote from: Tiger on October 07, 2010, 07:42:54 AM
:) Spark plug socket size for a Vision...18mm
8).......TIGER....... 8)
a thin wall socket works best
I'm just going to say this once...there are no shortcuts to cleaning a set of Vision carbs. Everything has to come apart and be cleaned. Rust and dirt clogs the passages and results in erratic running. You must get your tank clean, add a very good filter (finest particulate mesh possible) and then clean the carbs thoroughly as there are no quick fixes (or rarely). Emulsion tubes just pull out although if they are corroded they require a careful gripping by a good pair of needle nose to get them moving and extract them for cleaning. You don't have much of a lip to grip or try and blow them out with air.
Use a fine stainless steel wire to clean the choke circuit (haven't found anything better to clean corrosion in that very fine hole), and make sure you feel it go through the hole in the bottom as this can be the cause of poor starting. Make sure you do the jet in the bottom of the carb below the access screw.
Replace all o-rings on the idle screws and ensure they have the correct spring and washer combo, and there are no o-rings jammed in the passage (again from a past life and don't ask me how I know that happens).
And you need to check all jet types, sizes, locations to make sure someone did not screw something up. Most carburetors have something messed up because someone who did not know what he was doing got to it in a past life.
Much more could be said on this subject, but suffice it to say it requires a bit of experience or very careful reading of many past posts (and from someone who actually knows what they are talking about).
Good luck :-\
well said
I would listen To Cdnlouie.
Thanks for all the tips guys. You're really helping me thru this.
Progress...slow, but steady. Finished cleaning it all out again today. Reassembled the bike and with the aid of jumper cables it started right up. Idled nice and even, all the power is back, no stumble, etc. It felt great...better than it ever had before when I took it on my first test ride. However, once the bike started warming up I started getting a little bit of trouble. I think some of it may be attributed to a semi-dead battery as it hasn't been charged all the way up in nearly a month.
After fiddling with things a bit, I got some consistent behavior out of the vision. It will idle on it's own no problem at around 1300ish rpm. It will even rev to redline smoothly and everything sounds and feels right. However, if I really punch the throttle, it bogs and almost dies. It never really stalls out, but feels like it almost does. However, if I more gradually crack the throttle, it feels fine.
Now, I haven't properly synched the carbs yet. I basically just used the same settings for the throttle linkage, and have the idle mixture (the ones on the bottom right of the carbs on the left side of the bike) turned out somewhere around 2.5 turns. Is this bogging due to a poor synchronization? Or is it likely something more than that? I'm just wondering if I'll need to tear it all down again and do some more cleaning.
Thanks everyone :)
Quote from: 2002_wrx on October 14, 2010, 07:31:27 PM
.....everything sounds and feels right. However, if I really punch the throttle, it bogs and almost dies. It never really stalls out, but feels like it almost does. However, if I more gradually crack the throttle, it feels fine.
Now, I haven't properly synched the carbs yet. I basically just used the same settings for the throttle linkage, and have the idle mixture (the ones on the bottom right of the carbs on the left side of the bike) turned out somewhere around 2.5 turns. Is this bogging due to a poor synchronization? Or is it likely something more than that? I'm just wondering if I'll need to tear it all down again and do some more cleaning.
your next step is to sync the carbs... after that, throw one of these digital tachs on it to fine tune the "mixture screws"
http://cgi.ebay.com/ebaymotors/Hour-meter-tach-sx-KTM-exc-mxc-xc-mx-sxf-250-450-525-65-_W0QQcmdZViewItemQQhashZitem56403a8b87QQitemZ370444766087QQptZMotorcyclesQ5fPartsQ5fAccessories
NV beat me to the punch, but yes, now that you have it running, synq the carbs. don't worry about the bog 'till you have the carbs dialed in. also, keep in mind that carb synq, pilot adjustment & idle speed are all interdependent.
go slow, make incremental adjustments, not 1/4 turns at a time.
as far as the bog goes, do you have the updated carb/flapper?
reving under no load conditions will make some of these bikes bog. there are other things to consider such as amount of engine wear, valve lash, etc. allways check your progress with a test ride.
put a meter on your battery, what's it charging @ 2500 rpm?
Night Vision - hehe...sorry for my lack of correct terminology. Haven't really taken the time to learn the names of everything. Are these just the pilots? Or am I throwing out random words I've seen in posts? ;D
Thanks for the link; I'll get hold of one soon.
Lucky - I'll check what the battery's charging at next time I get a chance. Think my roommate has a meter - if not I'll swing by the store and pick one up soon. Yes, according to my understanding I do have the updated carb and the airbox flapper.
Sounds like you got something happening there. The only thing I will add as a thought to these previous good thoughts is that you might need another half turn or so on the rear carb mixture screw (out). I have found that the rear cylinder seems to enjoy more turns than the front. If the idle goes up as you turn it out, that's generally a good sign, if not, leave it where it where you have it.
Getting the mixture screws dialed in really depends on getting the bike running decent enough to idle at a proper rpm otherwise it is very hard to tell if you are improving the setting or not. Getting the carbs synchronized really works hand in hand with this setting, but you have to start somewhere.
Also, spray a bit of carb cleaner around your throttle shafts to check for vacuum leaks (Ie. change in rpm) as that will tell you if they are leaking and leaning out your mixture.
Oh...and check the acclerator nozzles for shooting down the barrels without hitting the throttle plate. They should just skim by the plate as it opens as well as clear the side of the carb body.
Sounds like you are having fun!