HELP! Repeated piston scoring on a MS500i

[EFSM]

Several weeks ago I replaced the scored piston in a 500i with a Meteor. The operator used it for the first time a couple of days ago and it scored again. This isn't the first time this saw has been problematic--it had a full top end rebuild under warranty (by another shop) shortly after it was sold. I'm not a Stihl dealer, so I don't have access to the software.
I ran the saw for a few minutes after I replaced the piston, but the first thing the customer did was put a 32" bar on and start stumping with it. It ran for only a couple of minutes. I checked the piston dimensions Meteor vs OEM and they are identical. The ring gap on both Caber and OEM rings seems a bit tight at .007, but there is no evidence of the rings binding up.

I wonder if this was a cold seizure due to not properly warming it up. Has anyone used ceramic coating on a chainsaw piston crown as a heat blocker? I'm seriously considering it. I'm sure people will be wondering about air leaks and running lean, but it just seems like these 500i's are too prone to scoring, especially for an operator who won't warm up his saw properly.

The first pic is of the ex. side of Meteor, the 2nd and 3rd are of the OEM Stihl piston.

 

[huskihl]

Although rare, some of them end up with fuel values outside of parameters and can’t recover on their own.

It needs an SDS software reset/update.