For what it's worth, I had a CH25 that I bought not running. It had been run hot and dropped a valve seat. I opted to put on two new heads because the one was destroyed by the valve seat slamming around. It had about 1200 hours so I also wanted to put in new rings. Kohler changed the piston and if I wanted OEM rings I had to buy new pistons, which I did. Reason I am bringing it up is that I learned they have a Nikasil lining in the cylinder. I measured bore size, taper, and out of round and it was all within spec so I just honed it and put in new rings. Seems to have worked pretty well. It runs great and inside the oil filter is bone dry so no blowby.
|