I KNOW THAT A B01A IS A OFFROAD MOTOR I JUST GOT A MRX4-R AND RITE NOW THAT IS THE ONLY MOTOR I HAVE. I WAS THINKING I COULD PUT A TALLER GEAR OR RUN A TYPE OF PIPE THAT WOULD GIVE ME MORE TOP END,THE TRACK THAT I RUN AT IS TIGHT ENOUGH THAT A LITTLE MORE TOP END WOULD BE ENOUGH.....THANX....MIKE