sealed motors... all retaliative, tough to regulate ... we worked a program a couple years back where everyone brought in a motor (new in the box) and a specific chain guard and top plate. dropped them off a week before the first event.. each one went on a shelf, the shelf in the barn had numbers. when you came to the track you picked a number and that's the motor you got. Add your clutch, mount it up and go play.
at the end of the night you pulled into tech and took the motor off right there, pulled your clutch and went home. we never tracked what motor went where, we just put them on the self.. so if you tinkered on it while you had it, those parts or work stayed with the motor when it went in the barn. oil changes every 3 weeks. at the end of the year, those who participated could take it home or leave it for next year. if you took it home, you needed a new in the box motor for the following season. covid put it all on hold