Jamin

Sold my 2005 Ski-Doo 800PT Renegade to a friend.  Yeah, I know - - do not sell anything to a friend.  Long story short, the 2005 had a complete rebuild done in 2008, new crank,  RK Tek drop-in kit with 13-1 cheater head.  Ran great for two years under my ownership.  My friend has put on 1500+ miles in 3 years.   Piston melt down in February this year.  Looks' like I'm working on the sled again.  Motor passed a leak-down test prior to disassembly, Both pistons have what is called a 4-corner seize.  The crown of the pistons both show damage from detonation.  Hopefully the cylinders are reusable.  This is a Power-Tec motor, jetted for the mid-west, 1200 - 1500ft altitude.  400 mains, .015 additional needle shim, 20 pilot jets.  My thoughts are bad-gas, low octane fuel, and/or water in the gas.  Any other mid-west RK Tek drop-in owners out there?  What are your carb specs for a Power-Tec motor?  Thoughts?