I have a Kohler M8 on my Troy-Bilt Tomahawk chipper, a replacement for the under-powered 4 HP Tecumseh it came with. I bought this engine off of CL, and was told it came off of a blower. I have no further information about this engine; the silver sticker with the serial #, model #, etc is completely blank, as if someone used too strong a cleaner and wiped off all of the words. It runs very well, except if it hadn't been run for a few months or more, I can only get it started by using starting fluid. The carburetor has been rebuilt, and the fuel is fairy fresh and treated with B3C Ethanol Shield. Since this machine is used only a few times each year, the spark plug and air filter are changed every other year, and changed (oil is change yearly). The carburetor is Kohler #41 053 27 (is this the same as a Walbro #K1-WHL)? I always close the fuel petcock and run the carburetor dry when I'm finished using it. The choke is definitely closed during these initial starts.
Any ideas why this engine so difficult to start? Any suggestions towards correcting this? Also, why would a fuel pump be needed on this engine? Wouldn't gravity supply a sufficient amount of fuel?
Thank you.