[fox46]

Get your hands on some LocTite 603 "green" Retaining compound. Use a Q-tip to coat the inside of the pinion gear before pressing it on. You have to install the pinion quickly and in one step otherwise the compound will cure and lock the pinion in place part-way through your install making it impossible to press it further onto the shaft. Be very careful to use it sparingly and do not get any on the motor's bushings. One of my teams' sponsor is a snowmobile repair and recycling company and most snowmobile (2-stroke) crankshafts are made in multiple pieces all pressed together hand held purely by interfereance. This compound is used with each press fit to lock the components together. It will not release unless it is heated. It is an excellent product and I use it religiously on interfereance fits.