OK guys, I'm about ready to admit defeat over what should be a very simple solution, supposing the cause can be identified.
I have old gas engines, farm tractors dating from 1918 and other cars. All have carbs and none want to flood except for my favorite, a 1927 C-cab TT. For 4 years it has been 100% reliable up to this spring, It spends the winters in a 24 foot enclosed trailer, all snug and dry.
This spring the vaporizer will not shut off the fuel flow. The tank is clean, filter clean and gas fresh.
The fuel bowl is clean, unwarped and has no dings. It has not had a bowl gasket-never needed it. The floats, new and old, are brass and are dry. I put a new float hinge pin in, another neoprene tipped needle assembly, new gaskets all around.
The float moves freely with no binding on the pin. The needle does not stick in the seat. The float is set now below parallel to the carb, having been set all over the place.
Blowing into the fuel petcock with the bowl level admits air as normal. Tilting the bowl in any orientation shuts off the air flow. With fuel coming into the carb, with the bowl off, fuel will flow normally until a very easy lifting of the float will shut off the fuel flow.
With the carb base assembled but off the engine the float will rattle when shaken. Bowl vent is open.
OK now, the $64 question...What the H is going on here? What obvious problem am I blind to?
Any replies, even those questioning my sanity, etc. will be gratefully appreciated.
Did you mistakenly replace the bowl drain plug with that of a NH ? Vaporizer drain plug has no hole drilled in the center to meter the fuel.
Steve is correct. I had the same problem back in the 80's. It turned out to be when I rebuilt the Vaporizer I used a NH drain plug that I had laying around. It caused a VERY rich mixture that the needle wouldn't adjust out. I reinstalled the Vaporizer drain plug and the problem was solved.
Vaporizer plug on the left, NH on the right.