your jetting sounds close for sea level,i ran pretty much the same jetting last year with fattys and rad valves.it could be like you said the guy you bought it from jerked you off.the different comp.#'s could be one cylinder went south,happens often,or you goofed on the comp. test.did you use the hand held kind you stick in the spark plug hole,or the kind you thread in?the first type is a bitch with out an extra set of hands.