Is this compression alright?

[thannah84]

I have been having some overheating problems with my 84' 2.5L I4 OMC Stringer.I wanted to rule out a head gasket before I replaced the Impeller..That is my next project....Been troubleshooting it last few days...Did a compression test tonight. The results are:

Cyl 1: 175psi
Cyl 2: 175psi
Cyl 3: 176psi
Cyl 4: 178psi

I don't know the manufacturer's specs, and my manual hasn't arrived yet so I thought I would ask.. Thanks!

 

[Paul eagen]

Re: Is this compression alright?

That compression is fine. My 2.5L is around 150psi. The most important part is that they are within 10 to 15 percent of each other.

 

[thannah84]

Re: Is this compression alright?

Thanks...I was kind of worried because the specs in the downloaded manual say 130psi....I hooked the gauge up exactly how the instructions said....I pulled the ciol lead wire from the dist, Pulled spark plug of cylinder i was testing, move throttle to wide open and crank starter until gauge did not move any more. Does this sound right?

 

[Robj]

Re: Is this compression alright?

Thanks...I was kind of worried because the specs in the downloaded manual say 130psi....I hooked the gauge up exactly how the instructions said....I pulled the ciol lead wire from the dist, Pulled spark plug of cylinder i was testing, move throttle to wide open and crank starter until gauge did not move any more. Does this sound right?

Yep and those numbers look great.

Have a great day

Rob.

 

[soaringhiggy]

Re: Is this compression alright?

those are great numbers, go fishing

 

[Paul eagen]

Re: Is this compression alright?

The commpression could be high if the motor was modified for more POWER arggg arggg arggg!!!

 

[thannah84]

Re: Is this compression alright?

lol...I don't know about modifying a 4 banger for more perfermance. It does what it needs to do when I use it...It gets me going 30mph in my 22' fishing boat...Just takes awhile to get on plane with it that's all....