My 91 f2 has carb / fueling problems I think. The idle goes from 1000 to 5000. When i rev it, rpms fall very slowly. Feels like a vacuum leak, but I have removed all vac connections and check the carb boots. A little history first. I have run my 91 with a dynojet kit since 92. Always ran fine. In 2002 I pulled the engine and stripped the bike down to install new bearings, bushings, and cam chain and guides. Fast forward 7+ years. I reassemble the bike, cleaned and double checked the properly stored carbs. Bike runs pretty good. Has a problem with flooding after running. I replaced the petcock and float needles with new items. Bike ran pretty good. Still flooding while sitting. Had to drain oil. Bike ran fine. Went to ride on freeway and bike began to run rough, eventually sounding like 3 cyls. Pulled carbs (4th time). Replaced floats with new stuff. Added fuel inline fuel filter. Bike still runs poorly. Will rev, but not cleanly. New plugs. Removed and plugged all vac connections. Same result. Anyone have any suggestions?

 

i just bought a 94 f2 a few weeks ago and it was doing the same thing on the freeway would run rough and it actually ended up killing over on me as if it wasnt getting fuel but i let it set for a minute and it started up and ran fine it did it again later the next day so i removed the fuel lines and blew air thru them to make sure they were clear and i drained the tank and under the tank there were some wires that i noticed were bare and touching so i respliced them and figured out that that is what was happening it was shorting out when i was goin fast and hiting pumps on the freeway cus it made them touch im new at all this but id check ur wiring and also a senior member on here i think it was sand man put a post up about coils and plugs which helped me too cus the original owner had the plug wires hooked up wrong on the coils and made mine run rough but now its fine and i also pulled the carbs 4 or 5 times but nothing was wrong with them so i was confused too

 

I saw the post about coils. I'll check that. don't have any bare wires. i marked my plug wires with zip ties way back when. thanks for the reply. Still looking.

 

maybe check ur coils and see if they are any good and then check ur throtle maybe its getting stuck open ? or check ur choke maybe its getting stuck and thats why it takes a bit for rpms to goin down?

 

my friend remove fuel filter, i have a fuel supply problem with a fuel filter and when i remove the bike runs fine again.

With your idle problem, i think you have an extra air leak, don't forget any rubber or gasket in carbs? on carb boots base, did you see if the metal are ok? without any break line.
or maybe you need to reset the pilot screw and a carbs sync.

Cris

 

yeah i think i need to get carbs cleaned and synced but for right noe it doin good gonna gets carbs done in couple weeks

 

well atleast you know what it is now thats a start! good luck with it

 

When was the last time you checked your valves? If your valves are out, it can make the idle rough and unclean. I don't think it'd do all of this though, but every bit helps (or hurts, in this case). I don't think it'd make things go this badly. You said you replaced he floats, did you replace the float needle? How do the needle seats look? If your float needles are screwed, it'd give you those flooding problems. How are the diaphragms on the carbs? Try sucking on the 2 lines coming off the tee's between the 1 & 2 and 3& 4 carbs, and see if all 4 slides come up evenly. If not, you may have to replace one of them.

I had the same problem on my F2, but what I did instead was make sure there were no kinks in my fuel line with the filter. It took some trying, but I always prefer to have an inline filter. The less crap that gets in my carburetors, the better.

 

I had the same problems with my revs taking their time. Turned out a perfect sync fixed it all up

 

Thanks guys for the ideas. I took the carbs off and blew them out again. I also removed and capped all vacuum ports. Bike runs fine now. I do however, have a substantial gas leak at the t-fitting into carbs 1 & 2. Oh well, what's one more time to remove the carbs. I'm actually getting quite good at it. My guess is one of the Cali EPA emissions diaphragms may be bad. I'll sort it out. Thanks again.