you cant hear the blow off valve when letting off the throttle? i had a 09 fst dragon. great sled but seem to be very high maintence. seems as if when your boost box at the throttle bodies created to much boost were the blow valve didnt release. that might be your problem. its open showing it has no boost. one thing that i learned off polaris files is having a leak free system. when theres alot of leaks the turbo free spins which then takes it out. polaris files guys are very helpfull