I changed niddle and seat. Only time it leaks is when engine is wormed up, then shut engine off then it go's to leaking. Got any ideas??

Set float correctly?

Got any ideas on the clearance between the float and the carb?

Niddle, what's a niddle? I had the same problem with the new float valves. I found a good original one and no more problems.

Stephen

Rick you had me going for a bit... I used to own a '25 TT with a leaking cab roof... turns out the vinyl I used for the top had a flaw. Nearly drove me nuts 'till I discovered the problem.

But that's not what you were asking. What Carburetor are you using?

Sometimes the float will get cocked in the bowl or the needle and seat have wear grooves that need to be cleaned up or replaced. I would check first for bent/worn parts.. floats sometimes get bent or the float itself may have a pin hole. As Steve pointed out, it could be that the needle and seat just need to be replaced. Good luck.

Rick,

You might check to see that all of the old gasket from under the seat was removed before you installed the new gasket under the new seat. Sometimes parts of the old seat gasket remain even when you think you removed it all. When you put a new gasket in the old gasket pieces can keep the new gasket from forming a tight seal with the carburetor body, causing a slow gas leak.

Respectfully suggested,

Trent Boggess

Sorry for the bad spelling, it is a Holley nh carb. with a new niddle and seat. It only leaks when the engine is shut off. I`ll take it apart later

Check your float with new fuels they are to heavy

So your saying I might need to adjust my float?

Set your float 1/4 inch above the bowl gasket flange when it is upside down. You should not be able to blow air through the inlet in this position if your needle and seat are good.

Often new needle and seat assemblies need to be polished in order to seal. Here's an easy way to do that:

http://www.mtfca.com/discus/messages/411944/469501.html