What is the compression pressure on a 40hp 2 stroke mercury?

[dalefan4lyf]

What should I expect for PSI on a compression check on a 40 hp 2 stroke mercury?

 

[fastjeff]

120 to 140 is a good range.

Jeff

 

[mike1947]

What if compression on top 2 cyl are way slower reaching 120 than the bottom 2 ??

 

[racerone]

That usually indicates a problem.-----Remove bypass covers ( if it has them ) and inspect pistons and rings.------Year and serial # should be posted too.