Is my engine worn out?

[hardwire]

I am still trying to figure out why this boat seems to have no power. The engine is a Merc 3.0L The first check was a compression test. I got 125-120-120-90. Supposedly it has been recently rebuilt...is it time to do it again already? Would compression like that cause my boat to lose a ton of horsepower? It seems to struggle just to keep on plane.

 

[Uraijit]

Re: Is my engine worn out?

Did you do the test with ALL of the spark plugs out?

That #4 cylinder is too low. Might check the valve lash before you go tearing things down. If it was recently rebuild, it's possible that they just didn't get that right...

Did your compression numbers come up at all with a few squirts of oil? If they come up with the oil, you've got worn rings. If not, it's probably in the top end somewhere. Do a leak-down test to verify.

 

[Bondo]

Re: Is my engine worn out?

Supposedly it has been recently rebuilt...

Ayuh,.... Those #s aren't very Good,.....

Diagnosing Why is the next step,... Uraijit plan is a Good1.......