If my memory is correct , the Wico flywheel is about 2 pounds heavier ( mostly Zinc ) Phelon flywheel is about 5 pounds , mercury outboard guys have same trouble with magnets falling off ,,, especially when "banged " or shocked Phelon mags have alnico magnets that are sweat brazed to the flywheel , Alnico cannot be drilled ( too hard ) and too much heat removes the magnetic " hootsewhatsees" I'm thinking about removing all the magnets on a damaged flywheel and attaching rare earth magnets for more punch,,,,,, Larry.