Need some help w/ 91 VFR750

I just recently purchased my 91 VFR. It has been sitting for 2 years. Well I got it started and it actually runs okay considering. My problems I believe are with the carbs. So let me tell you what I have done, I cleaned the fuel tank, replaced the fuel filter and have been running Sea Foam in the gas(I'm on the second tank of fuel) The Bike is very hard to start if it has been sitting for more than a few hours. When it does start it smokes bad, kinda like the cylinders have gotten washed down with fuel. It will continue to run like crap at lower rpms and wont idle at all. After it has been running for a while and its good and warm it will idle okay for a little while. If i shut it off and only let it sit for a short time it will start right back up but it revs very high for a fews seconds then dies out. So I know the carbs need to be taken off and cleaned. But I am not sure what exactly is causing these problems. Is it possible the bowls are flooding over into the cylinders? If so what should I look for once the carbs are off? Oh yea, while I'm trying to start it after it has been sitting for a while if I touch the throttle all hope is lost. Another thing is where is the best place to get carb kits? I called the dealer and they want $40 per carb just for gaskets and $45 per carb for needle and seat set. I know I am asking a lot but I need some help.

 

Look in airbox after removing the air filter and you will probably see fuel dribbling out of carb throats, sign of sticking float needles.
you need to clean and inspect ... may not need to replace parts, although the slow jets may be plugged beyond redemption and are cheap .

most parts can be reused.

 

so should i just buy the gaskets sets from the dealer or will i not need them?

 

i would go with gasket kit while u have carbs out check and see if floats are leaking (hold them under gas and look for air bubbles) if they are leaking they will not float:ranger: :typing:

 

what gaskets exactly ??
each carb has only one gasket.....and that might be in ok condition.

 

There's no way that the float bowl gaskets are $40 each. Maybe for the set, but not $40 each.

On a bike of this vintage, I would suggest replacing them. I was able to get away with reusing the gaskets on my '96 and have no leaks, but it would be a huge pain in your ass if you went through all the trouble of cleaning the carbs and then finding ot the bowls are leaking after re-assembly...

...trust me. I've been there with other bikes.

 

Bikebandit's 'gasket set' has all the gaskets necessary to rebuild a carburetor. That's why it's so expensive. I don't see a way to buy just the float bowl gasket for a '91 given what the parts fiche diagram looks like.

 

91 carb issue

Or you can take the easy way out.

Pick up a second set of carbs. Rebuild them off the bike. All I did was to remove the bottom, spray each little passageway down and reassemble. Make sure to put the idle arm in the right position. Once clean and dry, remove old set, install new set, reattach all cables, hoses, etc and go. Make sure to change the fuel filter after cleaning the fuel tank. Install new fuel with techron and go.

BTW, I've got a second set in a box. PM me if interested.

Larry

 

A local salvage dealer has a set for $100; I considered picking them up to do exactly that.

I have a different working motorcycle, though, so I don't need to rush - but I might do it anyway. That way, even if I mess up a rebuild, I have a second set of carburetors

 

sounds a lot like mine did right after I bought it. I ran about 5 tanks of seafoam through it, rode it a lot, and kept telling myself I was gonna take it in to get the carbs cleaned out. Made an appt to do so, and it started running perfectly. I guess the crud eventually cleaned itself. I'll get it tuned up completely after the summer season, but right now it's running like a top, idling at 1200 steadily, and pulling like crazy above 8k rpm's like it should.

 

Turns out that disassembling the carburetors is not hard; it's getting them off that's hard. It required a significant amount of prying force to get them off. The slow jet in the #1 carburetor is completely blocked - and that's the only one I've taken apart yet, so...

I'm waiting for a few more parts from Bike Bandit (new carb boots, 3 more gasket sets ... etc.), but I expect to have the VFR running in 2 weeks or so. The air injection system filter disintegrated when I touched it, so I'm replacing that too. I'll probably pull the wheels off and take them in to have the tires done while I'm waiting.

 

Take pics.....I would love to be able to do my own carbs.....All i need is a how too

 

Ok, the carburetors are rebuilt, working great, and the bike's running well. I have a step-by-step for "how to rebuild a 90-93 VFR carburetor" in the works; I have to get the last set of pictures off the camera and comment on them.

It's really not that hard. I will say that anyone who pulls the carbs off a 15+ year old bike should just plan on replacing the carburetor boots. They are cheap and new carb boots are *significantly* more flexible than hardened old ones.

It took my buddy and I an afternoon with a six-pack, a giant screwdriver, and a Stanley FUBAR to get the carbs off (after everything was disconnected). It took me about 3 minutes to put them back on. It was very anticlimactic.

 

I've found that if the boots aren't cracked, just hard. I put the boots in boiling water for a few minutes and their nice and plyable and will slide on nice and easy.

Robert