There has been some piston failures in the ctec2 6000's and was in the 14'-15's for the most part. They first started seeing it in the cross country racing, on very long pull's the ECU calibration was not giving the engine enough oil on the R-XC's their for a ecu update was put out to add about 2% more oil on top end. Another reason for piston failure on the ctec2 6000/8000 is ingestion of snow into the intake, I have a 14' RR 6000 that I just picked up cheap with 1840 miles with a shattered intake skirt. The owner said his son was riding in very deep powder when it happened and after removing the hood to figure out what the problem was the engine compartment was full of snow along with the intake.
Have also seen a few new 18'-19' 8000's with broken intake skirts with snow also present in the intake's, either people are not getting the hood back on correctly or they have a poor seal from the start.
Active member and Trail Coordinator North Branch Snow Drifters