You would have to get it really hot to damage the crank. You would want to concentrate the heat carefully on the mag hub, not the crankshaft. I would be more worried about ruining the rubber crank seals.

I am trying so hard not to jump in here and complain about liability..... The gov. is all too happy and willing to control every aspect of our lives; why can't they solve this horrible, debilitating liability problem??

AV8TOR