Hey matt i dont know how long they would last, i know from personal experience big 2 stroke air cooled dirt bikes wont take the high rpm runs and sieze up.
Snowmobile engines i think are more durable.
But i am not going to dig too deep without finding someone that knows a little.
The old girl was the fastest 0 to 60 stock that i had ever seen in its day but i was 110 lbs lighter back then at least it wont spin as much