Originally Posted by Nemosengineer
Sounds like you should be looking for a snowmobile engine as the CVT is standard for that application. A 800cc two stroke twin could be quite exciting in a scooter chassis...
The snowmobile clutch is also probably the size of the current engine. The ratios are way different.
I would think that for cooling go to a liquid cooled engine and you can mount the radiator up front.
Many motorcycle engines have transmissions that are integral to the motor. And many scooters have engines that are "layed" over.