Anyone know who sells these engines ? My son bought a used sts .21 at the track Saturday after his race engine finally died. It says sts on the head & some other stuff in what looks like japanese . He only paid 60 dollars mainly to pay for the v-spec carb. it had. Upon racing he is impressed . That engine is a screamer & it actually ran 9 mins 30 secs before running out . I can't believe it. Anyway the bearings feel a little rough so we want to replace them. Thanks for your help guys.