I'm not trying to say that your wrong, but you have been given some very poor information.

Any single cylinder motor that is not equiped with a counter ballancer, will vibrate significantly. A CR500 motor is not counter ballanced, and when mounted solidly in a quad frame, the vibration is almost too much to hang on to for more than a couple of minutes. Keep in mind that this is only 500CC's and a two stroke motor. 650CC's and four stroke will be A LOT worse. The cases for the CR motor are designed to deal with this added stress of the harmonics created and can withstand it. The Rotax motor is not designed to deal with it. Rubber mounting the motor might make it ridable, but it would still never last.

Regardless of power gained, you couldn't get me to do this if you did it for me for free, UNLESS there was a 3-6 month warranty on the entire motor after it was done. I don't think any builder would be able to offer that warranty, so I would stear clear it it were my motor.

Keep in mind, I have nothing to gain or lose from this warning, just some friendly and free advice. Good Luck

 

So what if is doesnt work. I am just glad some shops are at least looking into the DS. Opens up the door alittle ya know!

 

balancing the crank will stil be a positive though so go for it

 

Every one that is lightening their cranks is throwing the balance off? Which side is heavier from the factory? The rod and piston or the counter balancer?