I stripped the mc16 engine today for some more tuning and a bit of maintenance. Once I'd lifted the heads off I was greeted with some very odd piston damage, so I took them out for closer inspection:







All in the same spot, just above the ring peg. Really weird for them both to have gone, possibly a fault with the piston?

Any ideas?
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More **** two strokes than you can shake a **** stick at.