1995 Johnson 88 SPL piston issue

[Case20]

I recently bought this engine and the compression tested good on the cylinders. I’m in the process of changing out the head gasket and found the top right piston looked like this. Any idea of what might have caused it and can I just clean it up and keep running it

 

[racerone]

Stop dreaming.----The motor needs to come apart for a rebuild !----I do not see how compression was good on that cylinder either !

 

[racerone]

Who did the compression test ?-----When was the compression test done ?----Last month or the day before you took he head off ?---See that rubber thingy / tube in the water jacket ?-----Looks like it restricted flow of cooling water and #1 piston overheated !

 

[faztbullet]

Pre-ignition damage....needs rebuild with 4 new pistons and new pack

 

[racerone]

The pre-ignition damage can be " buffed out " I think.-----It shows damage from a broken piston ring too.----The question is ----Who did the compression test ( seller ? ) and when was the compression test done ?