If your rebuilding the motor, you really would not need a new piston and sleeve, just someone reliable to pinch it, and do ceramic bearings wear out? I guess the biggest question would be, do you want that new motor smell again, as sometimes motors just seem to loose that tune ability, like the needles are getting worn out and you start chasing tune, but for me personally is, I generally have a motor pinched at 2-3 gallons, and new rod if needed and generally they are gone around the 6-7 mark, then someone else can play with the tune
