92 Streetfighter project will not idle

My 1992 Streetfighter project is giving me issues. I bought a set of carbs off ebay and the motor. The bike runs great above idle but runs rich below 2000rpm. When I pull the front plugs they are wet. I have cleaned the carbs and they look excellent throughout. I have owned 4 VFR 750's and never had an issue like this. Any suggestions? I haven't messed with the float settings, but I don't believe that these carbs have ever been touched.

 

aIR FILTER IS CLEAN ?? You're sure the choke plungers are retracting fully, nothing bent, and the cable isn't stuck ??

Symptoms you describe suggest that you need to count the # of turns the idle mixture screws are open as a baseline. If anything more than 3 turns out, try turning them in 1/2 turn at a time until it quits wetting the plugs. Or try turning each screw in until that cylinder quits firing, then open about 1 to 1 1/2 turns. Do all 4.

Have you ridden the bike at speed yet ??

 

Air filter is ok, choke plungers are retracting and the choke cable works well. I have cleaned the carbs without seperating them, but I havent touched the idle mixture screws, I am not sure where they even are. The bike runs well at speed and will idle for a little while but then starts to die ifyou do not rev it back up. As it begins to die the exhaust gets way rich. I paid $300 for the bike so i am probably expecting too much. Thanks for the advice sqirrelman, I will look for the mixture screws.

 

Carbs that old have most likely been tinkered with. Check float height and the needle tang needs to be bent correctly also. Did you make sure ALL the fuel/air circuits are clear that run inside of the carb bodies. Just because they look clean doesn't mean they are.

 

I took extra precaution to blow out all passages when I cleaned the carbs with 120psi. I will have to take them off again to check the float levels on the front two carbs. Thanks for the advice.

 

Yep, wherever the plugs are getting wet at idle you should look for problems with leaky float needles or incorrectly set floats, just as Grey suggests.

 

Clean looking hybrid there, hope you get it sorted!

 

I wouldn't bother:banana:

 

It requires skill and intelligence, we wouldn't expect you to.

Vfrcbr919 you'll have it sorted in no time enjoy the project!

 

I had to get a replacement set of carbs for my gen3 bike that I got, previous owner butchered the brass parts

 

If you didn't touch the idle mixture screws you didn't clean the carbs properly. :eek-new:

Blowing out jets with compressed air should be done AFTER probing slow jets with a suitable steel wire.

 

That is one hell of a $300 bike! If the bike runs at all you are very close on the carbs. I will ditto the group consensus, you have a float needle valve issue or float setting. It does sound like the front two carbs are over flowing.

 

I have another set of carbs that I have cleaned and inspected so I will give them a try. Thanks for all the suggestions. The bike only cost $300 but I have put another $1000 in it!

 

got mine for $500 You could always cut your loses and sell the rear wheel for what you paid for the bike :vtr2: stick with it, you will win!

 

I actually have a torch head cleaner that I used to clean the slow jets

 

So the wire went all the way through as illustrated above ??

 

The smallest wire within the torch head cleaner would go completely through. I sprayed them out with carb spray and then held them up to the light to verify that all holes were unobstructed. I have gone through another set of carbs that I had and am going to give them a shot.

 

I don't believe that merely seeing some light through is sufficient to indicate that they're fully open. I know it in fact, as the hole can be slightly plugged while still passing light.

 

So I cleaned the original set of carbs that came with the bike that were really crusty and put them on. Suprisingly the bike now runs and idles like a top. I wish I knew what was wrong with the ultra clean carbs I bought of ebay, but I am thrilled to have this project almost complete. Thanks for the suggestions!

 

The carbs have a model number stamped on them. Do they both have the same number?