1987 Mercury 150

[FISHINJUNKIE]

What should compression be on all 6 cylinders? I done a compression test on this engine today cause i am thinking about buying the boat this engine is on. When i done the test on all 6 cylinders gauge reading was 93psi per cyinder.Is this normal? Thanks

 

[Faztbullet]

Re: 1987 Mercury 150

Try a different guage as that is low(95psi)...

 

[FISHINJUNKIE]

Re: 1987 Mercury 150

Gauge is brand new OEM,i am new to boat engines i've been told if all cylinders are close in Psi should be ok motor.Could have been i did compression test wrong and getting a false reading? If compression is that low what does that tell about engine?

 

[j_martin]

Re: 1987 Mercury 150

Like bullet says, try another gauge. It's about 25 lbs low.