friend brought 1976 25hp johnson to me not running. Went all out and changed points, ignitions coils, an pick-up coil (laminate coil). Started rilght up but has a "clanging" that is scary. He had tremendous tightening of the flywheel nut ( I used a puller) Plus he had the throtle low speed very hijh. He said it ran briefly and then cut out. Could he have tried to run it on one cylinder thus effecting the oil to the other cylinder and the combo resulted in interna??amage? Could excessive downward pressure have damaged any bearings or cages there- of? So far, there is no excessive wobble to the crank or flywheel. Help!

