dutch25

Thanks for the suggestions. and help. Still not figures out yet. In the first post I said it is a down draft carb. It is actually a up draft carb that sits just under the intake manifold. We have bypassed the fuel lines and pump until we know the engine is running right. We are using a electric fuel pump and a gas can for a tank. Has anyone ever rebuilt one of these carbs?

Hi, first time poster. Great forum here. My dad has a 1948 EF Mack truck that has been in the family for over 40 years. It has the original EN290 motor with the Zenith 63AW12 down draft carburetor. He rebuilt the carburetor but it still will not run. The motor runs if you prime the cylinders so it is not a ignition problem. It seems like it is not pulling gas to the engine from the carb. We can not find any obvious vacuum leeks. Does anyone here know about these carbs or have an idea what may be the problem? Any help with this would be greatly appreciated.