leaking carburettor

Hi everybody,
I am running a projet bike for one month on a Kawasaki KZ750 LTD 1980, and I have been able to fix the main problem who was the ignition.
Now, when I ride it during 30 minutes, and I stop the engine, the carburettor is leaking by the overflow hoses until there is no gas left in the tank. little by little in small quantities.
What could it be ? the main jet ? the floating bowl ?

Post edited by: drakkar, at: 2006/05/11 20:50

Sounds like a float problem to me. I would check to see if the float is sticking or if it isn't set for the right fuel level. Try using a clear tube on the overflow and open the overflow valve while holding the tube up against the carb. look at the level of the gas vs. the bowl. If the gas level is higher than the the bottom of the screw plate (1/8th inch from the top of the bowl) then you need to adjust the fuel level and/or check to see if the float is sticking.

Hope that helps
Good luck

I ll check it out this weekend.
Some others guys told me it could also be the float needle in fault.

If the float needles have rings around the tips caused by wear, they may not seal anymore. They aren't expensive to replace, and you might be wasting your time trying to adjust the float levels until you know your needles are sealing off the fuel.

I had the same prob.Ended up to be a hanging float,but before I figured that out,I installed a "temporary"fix that actualy went for two years.I put in a fuel shut off valve from the lawn mower place and turned fuel off as soon as i stopped engine.My fuel petcock was messed up at the time too(not shutting off fuel when there wasn't a vaccume)If you a real cheap skate,use a pair of vise grips with two small pieces of wood and clamp on fuel line when stopped.Guaranteed both solutions will work until you get around to yanking carbs

Actually, I already took off the carbs and tried to check out the float needles. I have been able to find them, but I didn't see any dirt in there. The cone of the needle are not scored and not pitted. So, is it possible that the needles are bad anyway and don't do their job properly ?

It is possible that the needles are bad. Also that there is dirt or a film of dirt in the seat where they sit. A good trick is to use a Q tip soaked in carb cleaner and wipe around the inside of the seat (which is probably brass) and around the tip of the needle.