compression low or okay?

[gustafsonerik]

Did a compression test on my 85hp and it was the following 90top 87med 83low it runs okay now(thanks to maximum) but should i be worried???

 

[Mark42]

Re: compression low or okay?

Did a compression test on my 85hp and it was the following 90top 87med 83low it runs okay now(thanks to maximum) but should i be worried???

That does seem to be on the low side. The specs on my 1985 85hp says 150psi, mine measures 130psi on all three. Generally anything under 100 indicates wear.

 

[maxum247]

Re: compression low or okay?

Did a compression test on my 85hp and it was the following 90top 87med 83low it runs okay now(thanks to maximum) but should i be worried???

I'm just curious what method of checking compression you used?

 

[gustafsonerik]

Re: compression low or okay?

i'm pulling one plug at a time then replacing it when done,is that correct????

 

[maxum247]

Re: compression low or okay?

Type in (compression test) under "search" at top of page! I think you'll find instruction there on compression test! Good Luck!

 

[jerryjerry05]

Re: compression low or okay?

Pull all three plugs and open the throttle all the way and use a GOOD tester.
Do all three and compare. They should be within 5-10# on a good running motor.Jerry

 

[Mark42]

Re: compression low or okay?

Don't forget to have the water muff's attached. Doing a compression test is spinning the water pump dry. And a small shot of oil in each cylinder will give you the optimum compression reading and keep the cylinder from running dry and scoring.