Leaking Fuel for the gazillionth time

[FJ1200W]

Bikes parked, leaks fuel -

I replaced the float valves, blah blah blah, even installed a cute little shut off valve -



Came home the other day, parked the bike after running the fuel out of the bowls.

Next day, it leaked, a lot.

Then I thought about it - I just filled up.

I bet I have been overfilling the tank - and when I park it hot, even with the fuel shut off, the fuel expands enough from the heat to overflow from some vent tube -

Could be true - thoughts?

Thanks in advance

[ribbert]

Well, if you have a shut off valve (and assuming you have the off/on position correct, if it's a valve and not a tap, the picture shows it "on") it can only be coming out the overflow and yes parking it hot and full is likely to make this happen. Particularly if you fill it with the bike vertical then park it on the side stand.

A shut off valve is a good idea but a manual unit under the side cover seems a bit cumbersome and over time you get lazy if it's not convenient and stop using it, or, break the tabs off the side covers from constant removal. You could put a solenoid valve in there wired to the ignition.

Easiest way to diagnose your problem would be to not fill it right up, park it and see what happens.

I'm in the habit of never parking my bike full, but only because of the FJ's propensity to leak fuel past the fuel pump and a full tank increases the head pressure and therefore the likelihood of that happening.

IMO

Noel

[Pat Conlon]

Also, I do not fill my bike on the center stand. When parked on the side stand fuel can leak out the cap.

No big deal on the '86+ FJ's with the recessed cap and drain hose, but absolutely devestating to the paint on the early '84/85's with the non recessed cap.

[mark1969]

I kept getting fuel overflows - replaced the needle valves, didn't work. Eventually I replaced the o-rings on all the connecting tubes between carbs and it has been fine since. I put that down to the fuel pump still delivering fuel as there was not enough pressure build up due to the defunct o-rings?

I don't know, but it worked..

[bikemad]

It's good to know that I'm not the only guy having these problems!
I'm about to put a shut off valve in the system that I'll activate when the bikes parked up.
I've had the carbs apart and nothing seems suss.
Mines a '89 model 3cv.

[CutterBill]

Ty-wraps as hose clamps?  Fail.    Metal clamps only, please.
Bill

[ELIMINATOR]

I tried tapping the offending carb with anything that would reach the float bowl, as suggested on this site before. I cured it by blowing down the offending overflow pipe when the bike was running.

[FJmonkey]

Drain the offending carb, then fill it back up by starting the engine. Fresh fuel will flush the crud when the float is wide open. Works every time. 

[Zwartie]

This was my solution:



You can get more detailed info on this thread: http://www.fjowners.com/index.php?topic=16529.msg168451#msg168451

As others have mentioned, verify if it is the fuel tank overflow or one of the carbs. The shut-off solenoid won't do anything for the tank overflow but it should prevent or at least minimize the leakage should one of the carbs decide to spew.

Zwartie