Compression test, 88' Force 85hp

[bigmarcbancs]

I read in a previous post that on a motor similar to mine this persons compression test was 120 psi. My numbers are 102 psi for all three cylinders and held at 102 for a bit of time thereafter.
Is this a sign that a ring replacement is in store for me in the near future? If so, at what compression numbers should I change my rings at? Or does the motor simply just stop running suddenly? Perhaps 102 psi is nothing to worry about.
I havent yet obtained a manual so any feedback would be appreciated.

 

[jerryjerry05]

Re: Compression test, 88' Force 85hp

If all three are close to the same #'s,the difference could be in your guage. If it starts and you are still worried borrow another guage.If your still worried.
Running seafoam or Merc. engine tuner will remove carbon and posssibly raise the compression.Jerry

 

[jerryjerry05]

Re: Compression test, 88' Force 85hp

Compression on that motor should be 145-150# Jerry

 

[JB]

Re: Compression test, 88' Force 85hp

Will everyone please stop fretting about psi on compression tests!!??

Differences in guages, conditions and technique can make as much as 50psi difference in the SAME cylinder.

The purpose of compression tests is to determine if ONE cylinder does not match up to the other(s).

That is why makers ask for a range of 10% or less. If all cylinders fall into that 10% range and the engine runs well there is NO COMPRESSION PROBLEM.

 

[ck85abc3]

Re: Compression test, 88' Force 85hp

I read in a previous post that on a motor similar to mine this persons compression test was 120 psi. My numbers are 102 psi for all three cylinders and held at 102 for a bit of time thereafter.
Is this a sign that a ring replacement is in store for me in the near future? If so, at what compression numbers should I change my rings at? Or does the motor simply just stop running suddenly? Perhaps 102 psi is nothing to worry about.
I havent yet obtained a manual so any feedback would be appreciated.

I don't think you can read leakdown with a compression tester. Everyone I have seen holds the pressure reading until you realease the pressure with a button.

Are you using a leak down tester as a compression tester?