Piston hit compression tester adapter....

[cjbrill715]

The adapter was brass, and it left a crescent/fingernail clipping shaped dent in the crown of my pistons....It's a 25 hp evinrude, and it didn't break or flake anything off in the adapter into the cylinder, it just left a flat spot on the end of the adapter....My question is, will this hurt anything, or should i just run it??

 

[fdrgator]

The piston top is pretty thick. I doubt you did any serious damage.

 

[Docksidemarineservices]

If it raised a high spot, you may have a problem.

 

[joereeves]

I assume that "adapter" is threaded... and if so, apparently it's longer that the threaded & electrode portion of the spark plug?

 

[flyingscott]

How did you do a compression test if it hit the piston? If your compression tester hit the piston hard enough to make a dent, doubtful you could have pulled the motor over.

 

[cjbrill715]

I assume that "adapter" is threaded... and if so, apparently it's longer that the threaded & electrode portion of the spark plug?

Yes, threaded brass adapter. cheap $30 one from autozone. I should have took a closer look at it before using it. The piston hit the adapter piece at the edge/end of the threads, and left a diagonal flat spot on the adapter. It screwed out harder than normal, which was my first clue, but didn't appear to flake off any material....I took it out this morning, boat ran fine, my question is, is this something to be concerned about??...It left a crescent shaped dent in the crown of the piston...

 

[cjbrill715]

It screwed out noticeably harder than it went in, the adapter's threads where hammered over on the end/corner of the adapter. I shined a flash light in the bore, and saw a crescent shaped ding in the piston crown. My guess is the brass was soft enough to give before locking the crank out, but hard enough to dent the piston....Boat ran fine today, and compression still looks good...Just wondering whether to worry about it or not??

 

[cjbrill715]

If it raised a high spot, you may have a problem.

It doesn't appear to be raised....Is that a clearance issue, or a hot spot issue?.....If it's a hot spot issue, will it show on the piston?? like discoloration or something?

 

[joereeves]

What year is that 25hp Evinrude?

 

[cjbrill715]

What year is that 25hp Evinrude?

It's 1992.

 

[fdrgator]

The piston top is pretty thick. I doubt you did any serious damage.

I stand by what I said.

If it had enough interference to damage anything, you wouldn't have been able to pull it over.

 

[joereeves]

It's 1992.

In agreement with gator. That domed piston could be hit with a chisel.... wouldn't affect it.

 

[cjbrill715]

I stand by what I said.

If it had enough interference to damage anything, you wouldn't have been able to pull it over.

Ok, thank you. I'm new to this stuff.

 

[cjbrill715]

Thanks Joe

 

[cjbrill715]

In agreement with gator. That domed piston could be hit with a chisel.... wouldn't affect it.

Thanks Joe. i appreciate the help