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Compression on 1994 evinrude 88

papyson

papyson

Outstanding Contributor
i checked compression on my 19

i checked compression on my 1994 evinrude 88..the readings are 100..98..97...90...the motor is running fine but all i have with me is a clymer manual and after an hour of looking i cant find the specs in it..i would like to know the specs and should i do something about the 90 reading.?..the motor has more hours than average fisherman puts on one..thank you...
 
"Carl, the motor is coming on

"Carl, the motor is coming on 20 years old. Your compression numbers don't look too bad at all and are within 10% of each other, which is good (since your compression gauge is probably not calibrated exactly)....

Likewise, my manual does not have exact compression numbers, but think I have seen (or heard) that originally they would have been somewhere in the order of 120.

Someone should know for sure and will add it in
"
 
Graham...does it matter if eng

Graham...does it matter if engine is cold or warm when i took the readings?i took them with a cold engine in nuetral...i also found a statement on the web that evinrude did not specify compression readings on any of their engines...the reason for not publishing them was the variance in compression gauges from the cheap to the expensive ones..i am using a cheap one that i leave at camp...they just say that there should not be over a 15% variance between pistons in the readings...i not going to worry about it anymore...thanks for your timely answer...Carl
 
"Carl, yes that was kinda my p

"Carl, yes that was kinda my point - my gauge may read 110 and yours 95.

A cold engine will read a little lower since the rings etc are not "expanded", that's why in general I said your numbers looked good enough that I wouldn't be concerned about them.

More important that they are all within say 10-15 pounds of each other and all near the 100 psi mark...."
 
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