carburetor leaks

[jays-cb750]

I have a 82 cb750 and I finally got it back together. One of the four carbs( if sitting on it, it would be the one all the way to the left ) has a leak. It looks like it is coming out of the bottom of it where it has the part sticking out, don't know what that is called. It only leaks when the bike is off, running it does not leak.

 

[dirtdigger]

Sounds like the needle is stuck or not sealing or problem with the float. More than likely the needle is sticking, try tapping on the float bowl with the handle of a screw driver and see if it stops.

 

[Adumb]

I'm having a similar problem. I've checked my floats and they move freely but it still continues to leak from the overflow. Any other suggestions before throwing new parts at it? I finally have it put all back together and everything is dialed, but leaking gas all night is ruining my MPG.
Thanks,
Adam

 

[jobo]

I have a similar problem, the only difference being that the gas leaks into the sump. If I let the bike stand for any length of time, the oil level rises. I have had to drain and replace the oil four times. The only way to stop this is to close the valve at the tank and let the motor run till it runs out of gas. I have had two mechanics look at the bike, but it is still the same. I would have thought that the petrol would run onto the floor via the overflow. I would love to solve this problem.

 

[tommycarl]

I suggest that you take the carbs off and clean the needle seat. Put a q-tip on the end of a drill and polish the seat until it shines. Be sure the needle itself is clean and has no bad spots on the tip where it seals in the seat. Be sure the floats are adjusted properly if you have the adjustable type.

Before you put the carbs back on the bike, rig up a way to get gas into the carbs... a hose from an old lawnmower gas tank or anything with a hose you can connect to the carbs. Might be easiest to put a longer hose on the petcock and just use the bike's gas tank. Regardless of what you use, position the carbs level like they'll be when back on the bike and check to be sure the carbs don't leak before you put them back on the bike... saves taking them off in case you don't get things right the first time.

If you don't have an inline filter on the bike, put one on. All it takes is a small piece of rust or debris to get between the needle and seat to break the seal.

Turn off the petcock when you turn off the bike... way cheaper than than having to change the oil when gas gets in the crank case... or worse.