[undy]

If it's a bronze bushing you can have your local machine shop put a shallow knurl on it. If it's a needle bearing one then I'd use a prick punch and stake around the inside of the crank's end bore, where the bearing goes. All you need to do is "dig up" a little metal around the hole's circumference in two rows... and, viola!! a light press fit.. done it many times.

If you get carried away and put some deep furrows down you can always dress them up with a die grinder or the business end of a rat tailed file..

A press fit not only serves as a retention device but also serves to ensure input shaft concentricity. Simply put, make sure the bearing's centered.

Dave