It's all well and good dropping in a new lumb, but the frame is designed to take a 49cc engine. So is the chain and bearings and every other moving part. If you double the engine size you have to double the stopping power, else you'll just fly off without being able to stop properly, so bigger and stronger brakes. Having a very short wheelbase makes it flicky in the corners, but more unstable at high speed. Depending on what your idea of top speed is, you may need to extend the wheelbase to stablise it. The chain needs to be stronger as it's going to be under more stress as it's moving faster. Extended fuel tank if you're racing as it'll use move fuel. It'll be heavier but that's a fair moot point as it's a minimoto!

Does the engine actually fit? I know it's only a 110cc engine but I can imagine it being bigger than the 50cc that a MM should have.

Yamaha FZS 600 Fazer ... in gold! 

Ride safe, and look out for the Rainbow of Death!

^{There're only 3 kinds of people in the world, those who can count, and those that can't.}

^{Roses are red, Violets are Blue, I'm a schizophrenic ..... and so am I!}

^{Take pity on the man who invented the drawing board, when he screwed up, he had nothing to fall back on.}

^{Stuff everything, I've always got my bike.}

Yamaha FZS 600 Fazer ... in gold! 

Ride safe, and look out for the Rainbow of Death!

^{There're only 3 kinds of people in the world, those who can count, and those that can't.}

^{Roses are red, Violets are Blue, I'm a schizophrenic ..... and so am I!}

^{Take pity on the man who invented the drawing board, when he screwed up, he had nothing to fall back on.}

^{Stuff everything, I've always got my bike.}