Circlip damage

[btomlins]

I've finished tearing down my 1995 Evinrude 90 because cylinder #4 is toast. Upon further examination of block the circlip on the cylinder above has came out causing 2 grooves in that cylinder deep enough to ruin that cylinder also. Could that circlip get into the cylinder below it through the exhaust/intake ports and score the bottom cylinder too? Not sure why #4 scored? No head damage though. Is it common for these circlips to come loose?

 

[F_R]

Re: Circlip damage

Well, if you are asking if it is possible, I suppose so. But it would be so extremely unlikely that it would have to be considered impossible. It would have to somehow get out the exhaust ports and then find it's way back into the other cylinder's ports. Nah, that just ain't going to happen.

I have seen a few come loose. But often when they did, the engine had been torn down by somebody that wasn't trained. There is a right side up to a circlip. Not to mention being abused by improper tools or technique. How is the wrist pin to piston fit? Slopping around loose in there??

 

[boobie]

Re: Circlip damage

Years ago when they used snap rings you seen a lot of that but with new clip it's rare. As F_R said it could have been improper installation.

 

[James R]

Re: Circlip damage

Forgive me F_R could you clarify your comment on "circlip right side up".

 

[boobie]

Re: Circlip damage

I always put them with the open side down and the closed end toward the top of the piston.

 

[James R]

Re: Circlip damage

Don't you need to have the clip spanning the access cavity. The cavity is at the bottom of the pin bore. Makes sense to have the clip split at 45* or near that for ease of insertion and removal with less risk of deforming the clip going in. After many years and many motors I have never had a clip come loose. Just lucky? Each to his own I suppose.

 

[F_R]

Re: Circlip damage

Forgive me F_R could you clarify your comment on "circlip right side up".

Um, perhaps I spoke too quickly. I was thinking of Truarc snap rings. Is that what you have, or do you have the semi-circular wire deals?

Truarc snap rings have a flat side. The part that it retains, if it were to try to get out, would push that flat side against the side of the groove. Now, before somebody jumps me, yes there are exceptions to that rule.

 

[boobie]

Re: Circlip damage

F_R, what exceptions ?? I've always installed them the way you described.

 

[boobie]

Re: Circlip damage

James R, the cavity is at the top of the pin bore.

 

[James R]

Re: Circlip damage

Sorry my big mistake. The cavity is offset from the vertical by about 30*. That would certainly place the split at the top. No excuse, my bad.
Thanks for putting up with me.

 

[boobie]

Re: Circlip damage

No problem........