I would check the CVT tubing first, especially if you plan to hit any mud. But that's just my experience and James from JBS' experience. I posted a thread here titled CVT Tubing Issues. There is a video on youtube showing the problem. Also, since nobody every mentions this, make sure the first several drive cycles you do include lots of WOT for short bursts followed by zero throttle input and full engine braking. This properly seats the rings to the cylinder walls.