I went through my Holley carb last weekend by totally disassembling it and cleaning everything with Gumout choke and carb cleaner as suggested by Jim Trekell. This seemed to help a huge amount as the engine ran better, but not normally, after reassembly. This weekend I drained the carburetor, fuel line and fuel tank completely of the pump gas premium/AV gas mixture. The carb was installed back on the intake, the tank filled with pump premium fuel and the engine was fired. After tuning with a vacuum guage, the engine was back to running and sounding the way it should. My idle mixture screws in the primary side function as they should now. Also, there are no more noxious fumes being emitted through the exhaust. Were my problems linked to the fact that I mixed the pump premium with AV fuel in a 50/50 mixture? I don't know. The engine runs fine on pump premium and it can be run up to the redline with no problems so I'll probably continue in this direction. Maybe next time I'll try race fuel instead of AV fuel but for now I'm going to enjoy driving this L72 for a while before experimenting again. Thank you to all of the members who responded with suggestions.
Joe (45420)
Joe (45420)