I broke in my magnum 91 just the way the manual recomended, the second startup, the engine overheated quick and the con rod bushing on the crank went away, needles to say, it bothered me, I took an old crank and rod from another 91 magnum that wouldn't hold a head gasket and combined with a new A.S.P. liner, piston, ring from JUST ENGINES, made a great
91 that runs great, three 5 min. slightly rich runs and threw it in the air, no muss, no fuss, clean oil on the side [8D]