Rotax 4-TEC engine?
 

Some wishful thinking....

The Rotax 4-TEC marine engines sure seem fire breathers. They are light weigh and compact three cylinder 4 stroke units that make a lot of power.

These 1500cc three cylinder units make the following horsepower depending on model/state of tune:
130hp, 155hp, 215hp and 255hp. http://www.rotax.com/en/Engine/2004/...ine.Models.htm

What do you guys think? I think this is a much better engine than going the bike engine way. Yeh, I hear, what about the gearbox? I believe that can easily be overcome should one put your mind to that.
But I think it will cost a bank:(

i cant speak for these modern fandangled rotax's but in my motocross days rotax were the king of engines. My mate rode an armstrong around the world which had a single cylinder air coolled rotax, i think it was 500cc. The bike rattled itself to death but he never once had a single engine problem.