@Robert M posted:
Are you running a mechanical fuel pump or an electric fuel pump? I don't know if you mentioned it yet but what type of carburetors are you running; Dellortos, Webers, Solex? Fuel pressure has always been a source of running rich. Or incorrect float bowl adjustments etc. I'm in no way a carb guy but the rest of the group will need to know the answers to those questions so they can help you.
Mechanical fuel pump. Empire HMPX carbs with 55 idle jets. I have synced both carbs but only one on each carb? Not sure why! I will sync all four. Timing I’d set at 7.5 per Gervae Engines. New plugs made a big difference for the better.
I do appreciate everyone’s guidance