I don't seem to find a problem in my 29cc conversion from Oneillbrothers.com, I even bought the optional "stuffed crank" or lightened crankshaft for even more power for a U$15 premium over the standard 29cc big bore + stroker kit.

It seems perfect for the Smartech SMT but I can see that putting a tuned pipe with the motor will cause the front to come up as it is plenty fast with the stock muffler.

Top end is more than enough, anything faster would only be of use under straight line drag racing but if a tuned pipe is installed, it would be a little too fast to control.