RE: Ever had an engine that wouldn't lean out?
Thanks everyone. Disassembled the engine and pulled the tank, there were no obstructions in the muffler/exhaust port. No leaky fuel tubing (blew in one and plugged other, tank is sealed) High speed needle valve was 1 1/4 from bottomed out. Fuel residue inside engine did seem slightly gummy, maybe this is normal? (ashamed to ask since I've been in the hobby so long)
Also ashamed to ask, this engine has a small needle valve in the very front of the carb. Is this a midrange mixture screw? I know all the car engines have this but back in the day no airplane engines had a low speed mixture that I can remember. I thought it may the idle screw that limits how far the barrel rotates but this wasn't the case. I'm thinking about sealing the backplate and carb for airleaks also. We do this for RC car engines all the time, is vital there's no air leaks in car engines.
Sorry for the long winded post, thanks again guys.