Piston Damage

[river rat]

What would cause piston damage on my 1983 Evinrude 70hp?
The motor was rebiult 10 years ago and they had to use .20 oversize pistons so there's not much hope in repairs.

[boats.net]

Well Its hard to say with an certainty, however looks like you may have leaned out the number 2 piston in the pic causing the piston ring to let go.