Piston ring End-Gap for Evinrude 9.9???

boatster

Petty Officer 1st Class
Joined
Jun 13, 2004
Messages
331
I just want to see if I need to replace my piston rings. Does anyone know what the end-gap tolerance for the 9.9 1980-1988 Evinrude? Also is that all you need to check for rings, end gap? Thanks again.<br /><br />Boatser
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Piston ring End-Gap for Evinrude 9.9???

If you got them out, why not just replace them? Inside of $45 will get you two new standard ring sets. Just deglaze the cylinders. End gap with the ring inside the cylinder is a minimum .010.
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: Piston ring End-Gap for Evinrude 9.9???

If you have the engine apart, simply replace them. With out looking, the end gap is quite generous, .007 min.-.017 max.
 

boatster

Petty Officer 1st Class
Joined
Jun 13, 2004
Messages
331
Re: Piston ring End-Gap for Evinrude 9.9???

If the rings are within tolerance why would I need to replace them? I've generally always replace rings but my curiosity is getting the better half of me. :D If I can save $45 without doing any harm why not?
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Piston ring End-Gap for Evinrude 9.9???

The running surface of the rings are most likely feathered and out of true...After being run, they also lose some temper.<br />Ring gap should be about .004 for every inch of bore...ie, 3" bore, ring end-gap should be a minumum of .012
 
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