This I agree with Jack.
Many of the flywheels I have seen damage have been from techs taking shortcuts or not using the proper tools. So far in the 11 yrs of professionally servicing small engines I have only seen one flywheel failure. And it was this year when I came across a Briggs flywheel where the flywheel slipped from being under torque and the flywheel instead of shearing had rolled busting the center of the flywheel. This was an older design of the 21,28, 31, and 33 flywheel which Briggs redesign to make things better.
One biggest problems with DIYers and some techs is that they either under torque the flywheels or use an impact gun (rattle gun) to tighten these flywheels which induces problems. Another thing that makes me cringe is the use of a screwdriver or other object stuck in the fins so they can tighten the retaining nut or screw of the flywheel.
Personally I would never use a damage flywheel. I have replaced several old Briggs flywheels that were damage by hammers where someone was trying to remove the starter clutches. Of course I have that removal and installation tool in my tool now collecting dust.
