Hi:
I know this bolters problems, I have many of the same.
I wish I knew the solution my friend, but I an just as stymied as you. Rebuilt engine with everything renewed or rebuilt. When running it needs partial choke and runs rich though I have attempted to lean it. The carb is a brand new rebuilt, and a new in line glass fuel filter. We have adjusted the valves, timed it and checked for vacuum leaks. One thing I note is air bubbles percolating in the glass fuel filter when running, should they be there? and if not where are they coming from. The fuel lines are new from the tank to the carb. Thanks for the help.
Regards,
Dave