I owned 5 700 single piped sx/sx-r/mountain maxes. The best pipes are Bender(Dynoport); Power inc, end dumps or Hauck(CPR) They are very reliable piped but it cuts fuel consumption by 1/3. Pipes will add a realistic 20 hp all tho the pipe guys claim more. Stock sx,s like thinning the head gasket, reed spacers & drop the mains & needles 1 step. Run em at 83-8500 rpm stock. Stock clutching in em was horrible & they over revved badly.