TOPIC:

OK, I just replaced my fuel lines and float bowl gaskets. I cleaned the carbs during this process. I got it all back together, and it runs well. Only problem is now the two carbs on the left hand side are leaking fuel out of the air filter. It is a substantial leak, and I am a little bit befuddled. Anyone out there have any suggestions?

Checked float height using clear tube attached to drain tube on float bowl. Fuel height is good and even across all four carbs. Only the two left carbs are leaking in this manner.

it does this while on the stand? recheck your needle seats, perhaps the fuel tap is begining to dump a little fuel...what was the situation that you went thru the carbs to begin with?

Bike had the wrong main jets for the pods and straight through exhaust. changed from a 92 to a 102.5 main jet. Cleaned out some debris that was in the float bowls, and assembled everything back together. Took it out around the block (1/8 of a mile) and stopped at my driveway(Flat and level) Could visually see fuel coming out of both pods on the left side.

Switched back to 92 mains, and got the same result. Leaking from the left two pods just sitting idle while running. It doesnt leak when the bike is off.

I would bet its the seats,when idling its not demanding so much fuel and they are not checking off so the excess is coming out the mouths of the carbs,the mains got nothing to do with it

mine did the same on 1 carb after rebuild...i put new float hinge pins in and i dont remember if i changed the seats..anyhow my buddy and i yanked the rack off again and opened that one up
and dis and re assembled...i remember my hinge pins for the floats were a lot tighter than the old ones...i think yanking the pin out and putting it back in loosened it up just enough...been fine since....i agree that the trouble is not jet related.....it s in the bowl... just my .02.....keith

I agree, it is not jet related, but who knows right? Pulled carbs off again ... checked and rechecked floats, seats, hinge pins and such. All seem to be OK, i did have to make some adjusment to one of the floats, it would bottom out inside the bowl upside down without fully closing the valve. Thought I had it fixed, put back together, and still pouring gas out of the pods. Gonna pull them again and try adjusting the seats on all of them ... maybe switch from the two that are not leaking to the other side ... see if i can replicate the leak on the other side of the bike. That should tell me if it is the seats or not. I'll keep you posted.

Zephyus wrote:

... two carbs on the left hand side are leaking fuel out of the air filter. It is a substantial leak... Only the two left carbs are leaking in this manner.

Excess fuel into carbs may also be getting into the crankcase and contaminating the oil, a potentially disasterous situation.

Would sniff test the oil for any gasoline odor, and if so, change the oil and filter, and correct the problem before again running the engine.

Am suspicious that the carb overflow circuits are also clogged, because the excess fuel now being allowed into the bowls via leaking float needles (or whatever reason) is supposed to escape through the overflow circuits without rising up into the carb throats.

Good Luck!

Got the leak fixed, not sure what changed, but tore float bowls down again took everything out, checked it over, and put it all back in. Leak went away, but i'm not sure how. I will fire it up in the morning and see how she runs. I was aware of potentially getting gas in the crankcase, with the breather and all right there where it was leaking. I also did an oil change once the leak was gone, also did filter and plugs. It seems to be running ok, but I am concerned about the mystery leakage.

Zephyus wrote:

Got the leak fixed, not sure what changed, but tore float bowls down again took everything out, checked it over, and put it all back in. Leak went away, but i'm not sure how. I will fire it up in the morning and see how she runs. I was aware of potentially getting gas in the crankcase, with the breather and all right there where it was leaking. I also did an oil change once the leak was gone, also did filter and plugs. It seems to be running ok, but I am concerned about the mystery leakage.

Leak went away, but i'm not sure how. Probably because the float needle/seat interface is now sealing.

Here's my understanding about how fuel gets into the crankcase.

Excess fuel into carb bowl for whatever reason raises the fuel level above the normal operating level.

The carb overflow circuit supposedly allows a path for excess fuel to escape from the bowl.

If the overflow circuit is clogged or malfunctioning for whatever reason, the excess fuel keeps rising up into the carb throat.

Such fuel in the carb throat flows both directions -- back toward the air filter, and forward toward the engine.

With a pod air filter, the backward flowing fuel escapes through the pod.

With an airbox, the backward flowing fuel goes into the airbox, and then drains through the crankcase vent hose into the crankcase (where such fitment is applicable).

With either pod or airbox, the forward flowing fuel goes through the intake port into the combustion chamber, where it flows down around the piston into the crankcase.

Good Luck!

Zephyus, let's assume that your needles and seats are OK. I did not read that you had an inline fuel filter... this would be a good time to consider adding one.

Best of success.

Got on it this morning, and the leak is back. Not sure why, will be trailering it out to local shop to figure it out. This isnt the first bike I have worked on, and i am pretty mechanically inclined (I used to be a helicopter mechanic in the Army) and have rebuilt a few bikes. But this has me stumped. Thanks for all your help

besides the seats not checking off,the float level being too high,or the petcock not shutting off,I cant think of what it could be.....ever discover a puddle of fuel under it after sitting??