Jumping my snowmobile ?

The difference between stock sleds and the racing ones are engine modifications, and suspension modifications. You can use a stock engine, but the chaincase needs to be modified to take the pounding of the landing. Same with the suspension. It's not made to take that extreme amount of abuse. If you want to jump, buy a different sled that is made for jumping, or modify your sled to take it. Otherwise you're just going to have to keep buying new parts. It's not the takeoff that hurts, it's that sudden landing.