In Reply to: Help - 1951 8N Not Catching posted by Keelan on June 14, 2021 at 09:13:06:
You might try taking the carburetor off and completely cleaning it, remove the jets and all pieces that come out, give it a good scrubbing with carb cleaner and clean all the passages for both the main intake jet and the idle ckts. Put all back together with good gaskets, a new needle valve, etc. when back together set the main needle 1-1/2 turn open and the idle about 1/2 turn. My emphasis is on clean-it is hard to see if the passages that contribute to starting are working so they must be clean.
There are a couple of good guides to cleaning in the How To's here as well as a manual for the carburetors themselves that are woth reading to understand the importance of the various areas of the units.
Other area is vacuum leaks, make sure the manifold gaskets are good and seal the intake as well as the gasket for the carburetor to flange.
Just sounds like a fuel system issue.