hi there , i'm currently restoring a 1959 c15 and at the point of re assembly of the crankcases ... the crankshaft turns freely when the crankcase halfs are together however when the nuts and bolts are tightened up slightly the crank won't hardly turn ... only thing replaced is the roller bearing .... the bronze bush was untouched .... might try knocking the new bearing back out and re try with the old one .... any suggestions what may be the problem anyone ?
Have you checked the crank is running true. If its slightly out that would give the symptoms you describe.
hi and thanks for your reply ... iv'e sorted the crankcase problem - bearing not pushed onto crank fully .... next question ... should there be any play between the crankshaft and the bronze bush on the timing side ?