Make sure you check the width. Just put them on and don’t try to clean and lube them with lighter oil. The factory grease will keep the balls from clutching on the straight and provide the best lube when cornering. The seals will keep the dirt out for years. I use axle collars on both sides of the left bearing and only lightly snug the set screws with some loctite to keep the inner race turning with the axle. That’s it.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience