I have been talking to someone that has 15 years experience in design, manufacture and evaluation of 2 cycle chainsaw engines. His opinoin is that after some many gallons you finally get a good ring seat and that is when the problem goes away. He thinks a perfect ring seal on this engine is critcal because of the small cranckcase volume.

There would be a couple of ways to check his theory, compare the ring seal via a leakdown test between engines that fail and engines that dont. Or put some moly coated rings in that seat in 5 minutes run time. Or put a failing engine on a test stand and run it for 20 hours and see if iit no longer fails.

But the part that "wears in" after 8 gallons or so is most likely the rings.

Joe