a pickle of a carby problem....

new marvel schebler ma3 spav carby.
adjusted ok and runs the O-200 quite well.
idle ok and static peak rpm on the numbers.
leans out ok.

about 2 minutes after stopping the engine I get a dribble of raw fuel
out the venturi. I dont know how long this would occur because I turn
off the fuel. 100/130 leaded avgas is the fuel.

just pulled the little character off the aircraft and dismantled it.
checked for a leaking needle valve. no problems.
checked the float height, 7/32 on the nose.
blew air through the fuel line and moved the float to open and close
the needle valve. good positive fuel flow stoppage.

there are only 10 components in the entire carby, well thereabouts.
the problem should be caused by wrong float height or a bit of crap
stopping the needle valve from sealing ...but it doesnt appear to be.

is there any other problem that these carbys can have to cause a fuel
dribble about 2 minutes after engine stop?

I have to ask because I havent been able to buy a manual anywhere
despite trying for a month or so.

anyone with a clue as to what it could be?
the carby is zero time almost.
Stealth Pilot