low compression

[eve225]

I have low compression around 80 on one cylinder all the rest have 100, i was just wondering if this motor has alot of time left on it. or if i should think about replacing it, it runs great and gives me no problems, (knock on wood) what are your opinions. 1989 225 evinrude, with new power head in 2001

 

[JB]

Re: low compression

Have you decarbed it recently, eve? If not, try that and then do a new C-check.<br /><br />80psi vs. 100psi is a larger spread than is usually acceptable, but it could be simply a carbon problem.<br /><br />Good luck.

 

[Reel Appeal]

Re: low compression

100 lbs. is fine and it will run on that 80lb. cylinder(although 80lbs is borderline for that motor).My question would be why is that cylinder 20lbs lower than the rest?Some kind of damage has or is happening on that cylinder.If it was me I would find out why this is before it gets any worse.Could be caused by a lean condition on that cylinder(carb.)or mechanical damage,ect.With a new powerhead in '01 you should be all good.New(and used) 225's are in the 8 to $10,000 range,maybe more...Good luck.

 

[R.Johnson]

Re: low compression

At least pull the head, and take a look a look at that cylinder. See if there is any aluminum smeared on the cylinder wall, or if there are any scratches.

 

[OBJ]

Re: low compression

I think I would take R.Johnsons advice and pull the head. You could be looking at a scuffed cylinder usually caused by lean running condition. These just get worse. How long since the carbs have been overhauled? <br /><br />No, we aren't trying to sound like the grim reapers of outboards, but the spread in compression is enough that may warrent further investigation. Do a decarb as suggested by JB and retest. Post what you find using this same thread. Hopefully, that's all it is, is carbon build up.