That I have seen more and was related to the last batch "microcasted" pistons and since that they have switched to the CNC piston in combination with small lubrication ports just under the exhaust port and later on to coated pistons. Novarossi knows what did go wrong but do not tell....

We have discussed about this issue and someone mentioned it could be a cold weld due the tigth fit. Normally an engine will stop/lock itself when the engine is not fuly runned in and you want to go to fast during the warm up. With this piston it seems it locks itself and directly has broken loose to run on. I could be a lack of lubrication with a different material piston.

In my previous post I was talking about tiny visable scratches not a compleetle damage surface....