a more expensive but more reliable and faster route would to put a crf50 engine in. 88 race head kit. 117 stroker. tak 3 speed. and youll have so much more reliability then that strap on engine.

they sell complete race honda engines on 50riders.com and planetminis.com.. i assume this would be the same as in the pitbike world.. knockoffs will kick you in the *** later.