The YZ gets its first piston! With ~150 hours on it, and in the dead of winter, now seemed as good of a time as any. This video is for anyone who wants to do their own top end; step by step, plus some helpful hints I’ve noticed with the Apex head and sealing the cooling system.
While I did inspect the cylinder and measure ring end gap clearance, it’s not part of this video as everything was well within spec and nothing needed further attention. This is for a 2023, though I’m sure it will be applicable to many other years with only minor changes in disassembly. The overall process is the same.