What do you guys make of these compression numbers (1989/85hp 3 cylinder)

[Bigprairie1]

Guys
What do you think of the following compression numbers on a 3 cylinder 85hp (1989) Force?:
Top: 130 psi Centre: 85 psi Bottom: 124 psi
Do these look like a broken ring? or head gasket? or?
Any ideas? This is a pretty clean/fresh water local (parts) motor for sale so I was wondering if had non retrievable issues.
many Thanks!!
BP

 

[Frank Acampora]

Re: What do you guys make of these compression numbers (1989/85hp 3 cylinder)

I would lean towards either a damaged head gasket or stuck rings. If you have the option, look in through the plug hole at the top of the piston. If it shows multiple dents, that would be from a broken ring. See my thread: my new toy.

 

[jerryjerry05]

Re: What do you guys make of these compression numbers (1989/85hp 3 cylinder)

Like Frank says look inside.Your gonna have to pull the head anyway,so remove the head and look for damage.
Could be just the gasket??
They are put on with 20# tourqe so they should come loose fairly easy.Too tight? DON"T force them.
They can break and be a real bugger.
For the future.Something caused it to happen figure it out or you might be fixing it twice!!

 

[Bigprairie1]

Re: What do you guys make of these compression numbers (1989/85hp 3 cylinder)

Good info guys...as usual!!
I saw this motor the other day on Craigslist locally and thought I would maybe take a look at it. with that centre number being at 85psi I wondered if it was more likely a head gasket than a ring.
That said...and you know Frank, I'm going to be doing the centre piston/ring on my 90/90hp here when the weather warms up next month. It suffered a broken ring late last season and I started to prep it for a piston/ring renewal.
I thought if it goes easy....and I've never worked on this motor much before....then I'd use my 'new found' experience to maybe do the same to the 85hp motor referenced here.
All Good
BP

 

[jason32038]

Re: What do you guys make of these compression numbers (1989/85hp 3 cylinder)

Buy it if you need it. At 85 psi the cylinder should be in decent to good condition. With a scored,burned piston your compression will be between 0-10 most likely. Could be a head gasket. Ask the guy if you can remove the head first or atleast the port covers of the low compression cylinder to see if you can find any visible damage. PS. Take your own compression tests if you look at it to verify.

 

[Bigprairie1]

Re: What do you guys make of these compression numbers (1989/85hp 3 cylinder)

Buy it if you need it. At 85 psi the cylinder should be in decent to good condition. With a scored,burned piston your compression will be between 0-10 most likely. Could be a head gasket. Ask the guy if you can remove the head first or atleast the port covers of the low compression cylinder to see if you can find any visible damage. PS. Take your own compression tests if you look at it to verify.

Yeah, that is a good point. I think I'll let this ferment a little longer before making a move or offer....but I might go have a quick look and introduce myself>
Good info & feedback guys!!!....as usual!
BP