A piece of advice from a former electric truck racer, DON'T use WD-40! If you need to clean it up, there are a lot of commercially made sprays for electric motors or use a spray Brake cleaner but use it outdoors! Use a light oil on the bushings or bearings. Kyosho used to have soome motors years ago, like back in the late `70's that they called 360's but were in a 500 or 550 can. It had something to do with the windings if I remember.