My 2 cents Haste, I have one on my bike.
Nice power, but make sure you have heavy duty wheels and good brakes. These engines vibrate too. The vibes go up with the cc.s.
I ended up mounting mine on isolators and now it is acceptable. Ever get an itch all over from vibration? Yes- it was that bad, even bought a clone go-kart engine, thinking the HF was out of balance- same thing.
Oh, the fuel milage is great on the big engine because it does so little work.