Japanman, the liner/piston sets are lapped iron/steel. when they first started using them over here they didn't last long because people were trying to run them with 12% synthetic oil i guess that's the reason for the large stock at the LHS
What were they running on 12% synthetic??? 50cc scooter engines??
I ruined a perfectly good osmax 10 by running it on 14%synthetic as used by a rccar club... (the club fuel guru had told me that his specialsynthetic was so much better at protecting that they couldn`t use it for running in)As it ran I could hear the power drop off..and then it stopped, never to start again!
It was a very powerful engine, too.
We all live and learn i guess.
Stefan