• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

leaking carburetor

Steve L

CB750 Member
Messages
29
Reaction score
0
Points
1
Location
Central New York State
I just purchased a 1971 K1. This is a pretty nice bike with great restoration potential, but previous owners have not always treated it well. It has some issues, but the engine seems strong and healthy. I only have about 300 miles on this bike, but when I first took it out, the carburetors did not leak. Last week, the bike was parked with the petcock on and I noticed fuel running out of the air box.

I pulled the air box and found that the fuel was running out of Carburetor #4. I pulled off the float bowl and found that the brass float had been "repaired" with some kind of caulk. Ah Ha!! I pulled off the carburetors and replaced all of the needle valves and seats. I also replaced some of the floats and set them at a uniform 26 mm height. I also found that a previous owner had soldered the float bowl vents on three of the four carburetors. I drilled them out and replaced the vent lines.

I restarted the bike and carburetor #4 still leaks.....this time out of the newly restored float bowl vent hose. This should be easy. The problem should have been with either the float or the needle valve assembly. I removed the float bowl expecting to see that it was overflowing, but the fuel level in the bowl looked good. Does anyone have an idea of what I'm missing???? I'm stumped and a little frustrated.

Steve
 
inspect the bowl vent tube in the float bowl they like to split...you have to look close they can be small cracks
 
Back
Top