And now for the top cylinder (pushes air most of the time instead of firing), argh.

Crown showing more impact damage than the other one? At least he same ring.


Signs of seizure??


And the real damage, heavy scoring down the length of the piston - rings are free still though.


.. And corresponding scoring down the length of the barrel quite deep indeed. Also out of focus, patch of plating that has gone there is another smaller patch missing on the other side ..


The locating pins for the rings are present, the only thing to cause that damage would be something injested or the tip of a plug getting down right?

AFAIK it was run with airbox but no filter..