The engine is stock accept the Muzzy exhaust. It needs a jet kit so its kinda dead between 2200 & 3000 rpm... kinda fun like it is... To take off I just tach it to about 3500 and dump it while continuing to twist. The key is to steer, you don't have to hold on thanks to the huge ass tail piece. I'm leaving for 11 days, I have the jet kit, all new carb rubbers and an oil and air filter, when I get back I'll put all of that on the bike.