Blown wrist pin circlip picture

[h_lankford]

<br /><br />1986 Johnson 60. Sudden drop at 3/4 throttle from 4500 to 4000 rpm, but still smooth. Back at dock 1 minute later with poor idle. Checked compression - none in middle cylinder. Here's the culprit hanging out at top of piston.

 

[lark2004]

Re: Blown wrist pin circlip picture

eeeuwww, This will need to have the engine pulled apart, and the bore inspected for damage. The piston is toast. You can replace just that piston pretty easily, What size depends on any damage to the bore. You may have to get that bore opened up and an oversize piston fitted.<br /><br />Good luck, and if you don't have one yet, get a manual!

 

[h_lankford]

Re: Blown wrist pin circlip picture

is that an Ozzie eeeuwww?<br /><br />here's another view, doesn't show damaged cylinder wall well, but it is about 0.040 in deep.<br /><br />

 

[lark2004]

Re: Blown wrist pin circlip picture

Yuck, I see that it has damaged the top edge of the port as well. You will need to speak to a machine shop about this. Find out what oversize pistons/rings are available as well.