Scooterotica

anyone got any ideas what would cause this ? its like a spot of weld on the crank taper , there is a smaller one directly opposite ,plus an indent that matches it inside the flywheel taper , the flywheel had previously been "lapped in" and had been off to check timing , scooter ran for 5 mins before flywheel started rubbing on cowling

I had the same thing, mine was down to a slightly loose flywheel.

I'm assuming you did have the woodruff key in place? Looks like the flywheel wasn't on tight enough.