Piston Failur question

[fgz]

I have a 1995 150 HP Johnson faststrike with the optical ignition. Piston #1 showing scoring but not as much as #3. #3has scoring all around it. All other pistons and cylinders ok! Water pump is good and no sighns of over heat on block or on the wireing on top or sides. Trying to diagnose the failed pistons! Any help would be greatly appreciated.

Thanks

 

[fgz]

Re: Piston Failur question

Does anybody have any inpute on this piston failure question?

 

[tx1961whaler]

Re: Piston Failur question

Pictures help.
Maybe clogged carbs leaned the mix out.

 

[wilde1j]

Re: Piston Failur question

+ on the carb thought.

 

[Faztbullet]

Re: Piston Failur question

Leaking block.. see attached link. I have built 5 of these 60 degrees over the winter and only one block passed the leak test.
http://www.mar-fab.com/MarFab_Tech_Bulletins_D9579.pdf