FWIW....I would leave the cam timing....What nitro % are you using?....Two turns on the h/s sounds a little "Heavy", but then again with high nitro, maybe not (you did say it was a little rich)....My experience with this engine is the reg. adjustment is approx 1 full turn "Above" the housing & the h/s approx 1-3/16...1-1/4 turns open (25% nitro, 21/22% oil)....Mich. elevation...