Fuel leaking from the carburetor ventilation

[DaanBaanvinget]

Good afternoon everyone,

I am in the process of rebuilding an FJ1200 3XW. I bought it as just a frame with an engine block, and I have since gathered the rest of the parts, with the engine almost ready to be painted (in its original color, of course).

I do have one problem: fuel is leaking from the ventilation hoses of the carburetor. It comes from two of the four carburetors (carbs 2 and 3) from the small hose (ventilation) located at the bottom, and from the larger hose going to the T-piece on one of them. I have completely disassembled the carburetor, cleaned it, and adjusted it. The float height is correct, and the carbs seem to close properly. I also replaced the fuel pump, but that didn't solve the problem. I was able to buy a complete new carburetor cheaply, so I tried that too, but it didn't fix the issue either. When I turn off the fuel pump, no fuel leaks, and when I pinch the fuel hose coming from the pump, no fuel leaks either. Of course, this is not a solution, but I was just trying to figure out what might be causing it. I noticed that the leaking only happens when riding, once the engine is warm. When I let it idle, even when the engine is warm, it doesn't leak. Does anyone know what I could do to solve this problem.

[Pat Conlon]

Did you replace the o rings on the float needle seats?

Get this kit, replace all your o rings, best $25 you will ever spend...guaranteed
http://www.rpmracingca.com/proddetail.asp?prod=carbkit

We have lots of help and tips on carb cleaning saved in our Carb Files.

Welcome aboard!

Pat

[DaanBaanvinget]

yes I replaced them, there are new float needles in them and new loat needle seats.

[Pat Conlon]

Did you use the correct needle seats for fuel pumps?
They are smaller than the gravity flow needle seats.

If you put the larger seats in there, the pressure from the fuel pump with push open the float needles.

[DaanBaanvinget]

yes i just checked and i used the right one i ordered this set.
all balls carburetor rebuild kit 26-1680

[firestorm]

HI FJ1200 LEAKS OUT OF ONE CARB
IF I PULL OUT THE CHOKE ITS STOPS LEAKING
HAVE NO IDEA WHY

[Pat Conlon]

HI FJ1200 LEAKS OUT OF ONE CARB
IF I PULL OUT THE CHOKE ITS STOPS LEAKING
HAVE NO IDEA WHY

Most common carb fuel leaks are from a
1) stuck bowl float, gummed up.
2) mis adjusted bowl float level
3) dirty float needle not closing or
4)  leaking o ring on the float needle seat.

Time for a carb cleaning, float adjustment and fresh o rings
http://www.rpmracingca.com/proddetail.asp?prod=carbkit

[Motofun]

The only thing I'd add is sometimes you can unstick a hung up float by tapping on the bowl with a screwdriver handle...bouncing off a curb has also been tried...