Not sure on that one. Don't want to guess.
BUY NEW PISTON AND RING KIT AND VALVES!! That cylinder is thrashed. No way I would put it back together with just new rings. :P If I lived in a third world country I would do some old school tricks to make things work but here in the modern world there is no reason you can't make it like brand new.. actually better than new for very little money. I know you are thinking about saving the money but a new piston and ring kit and valves won't break the bank and then take those to a machinist and it shouldn't cost you much at all to have him surface the cylinder. The valves you can lap into the valve seats in about 5 minutes and not break a sweat.
The bike will run so nice! Makes me want to go rebuild mine now just for drill!!
