Just a question about rebuilding my wifes 600XTC. The engine is starting to get up there in mules 17,000km and am wondering what sort of milage on the engine should I get before needing to do a rebuild. Also is it a good idea to replate the cylinders at this time or just replace piston,wrist pins bearings and rings and seals. The engine still starts and runs fine but is beginning to lack a little on the top end. Any advice is appreciated.