new Pep Boys 5.5hp clone engine

Im surprized that engine hasn't broke down yet. those engines are very unrelable and there not like the real thing

what is a clone motor all this clone talk..wow i guess u can tell im new man do u think u can help me iguess i posted in the wrong area but all i need help with is dang here it goes breef i built a minibike 4 my neice she grew out of the 3.5hp which i add did 35mph i bought a 6 hp it only does 25 barely beats the point how do i get more speed i was told something with a sping and the governor thanx man