[MattR]

2600 miles @ 15 mph average speed would give you about 173 hours. Actual engine hours may be different but this would give you a ballpark number to relate with. A lot of folks replace the topend yearly for peace of mind. Others put new rings in twice before swapping out the piston. For me, I would replace the topend between 175-200 hour range (2500-3000 miles). This is ever couple years at my riding pace. Even though it runs fine, the piston can fatigue and crack the skirt... then you have bigger issues.