but mine is a 30cc, not the originally mentioned 39cc!! should i try an 18x6? with the 14x8 it only put up 7800rpms does that sound about right or a little weak? i think that if the 14x8 is small for it then it should have spun it much faster than that? no suggestions on an engine mount?

edit: what rpm should i look for if i use an 18x6? 7000ish?