2002 Mercury 90 Compression Test

[JKNZ]

I tested the compression of my 2002 Mercury and #1 hole 110 psi, #2 hole 105 psi, and #3 is 80 psi. Is that in the normal range?

Thanks.

 

[JB]

Re: 2002 Mercury 90 Compression Test

Nope. #3 is sick, probably only carbon buildup.

Go to the Engine FAQs for how to do a decarbonizing with SeaFoam.

 

[alanaexall]

Re: 2002 Mercury 90 Compression Test

2 or 4 stroke ? top or bottom hole