Eddie Morgan
Member
I have not encountered fuel bowl draining overnight in a 1901. I highly doubt it is the power valve, that is typical of the Chander-Groves / Ford / Holley 2100 carburetors.
If you have not previously come across it this is a great source of information on your carburetor (use the arrows at the top of the web page to scroll through the manual):
http://www.oldcarmanualproject.com/manuals/Carbs/Holley/H1901-1952/MCarbHoll19011952.html
My memory from rebuilding a 1901 is that there are no gaskets below the fuel line in the float bowl. You have a confusing issue.
Yeah, there are only a few things in the bowl ... jets, power valve and main fuel inlet needle/seat. At the moment, I'm lost with this.
I downloaded a repair manual for the carb ( includes Lincoln, Ford trucks, etc) and trying to read my way through it. I did notice a drip coming from one of the small brass tubes which point to the throttle plates. I don't know if I can post a picture of it on here for clarity, other than my album.