Compression Numbers - 1986 Evinrude 110 HP

clm1117

Cadet
Joined
Feb 7, 2011
Messages
16
Left side top - 100
Left side bottom - 95
Right side top - 115
Right side bottom - 115

Motor has been sitting up for a number of years. Compression test done with throttle wide open but motor is cold because I didn't want it to start. I'm determining whether to spend the money to take it to a mechanic to get it running again.

So with those numbers what are your thoughts? Trash or treasure?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,089
Pull the left side head off.-----I think you have broken piston rings.-----Every one of the v-4 crossflow motors will suffer from that sickness.
 

clm1117

Cadet
Joined
Feb 7, 2011
Messages
16
Pull the left side head off.-----I think you have broken piston rings.-----Every one of the v-4 crossflow motors will suffer from that sickness.
Is it easy for a backyard mechanic to replace the rings? I've got the manuals. I'm guessing if the rings are broken they could have done other damage?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,089
You likely need 4 new O/S pistons and rings.------No point putting new rings on old pistons.------With a manual and some wrenching ability you can do this.-----Start by pulling that head off for inspection.-----I like pictures.-----Maybe it just needs new head gasket.
 

clm1117

Cadet
Joined
Feb 7, 2011
Messages
16
You likely need 4 new O/S pistons and rings.------No point putting new rings on old pistons.------With a manual and some wrenching ability you can do this.-----Start by pulling that head off for inspection.-----I like pictures.-----Maybe it just needs new head gasket.
Sounds good and reasonable. I have the OMC Service Manual. I'll pull the head off and post some pics. Maybe I'll get lucky and it's just the head gasket. More to come. Thanks.
 
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