Can a old mercruiser motor run very well with following pressures?

[SankorLiu]

The presures are following,
150,138,143,125,140,138.

Thank you a lot of

 

[SankorLiu]

Yes. the fourth cylinder is a little bit low.

 

[flashback]

What engine is it and is it running now? If it has sat for a while then your measurements are not useful. It will run with the numbers you have given but not well but I think if you get it started and running the numbers will be more accurate.

 

[QBhoy]

If that’s an engine that’s not ran for a while, you’d likely see better after it’s back in action. Easy for valves to pass a little on such an engine. Then be improved after she’s running. Oil around about her will also help.

 

[Lou C]

Was that a cold or hot compression test? For it to be accurate the engine should be warmed up & throttle wide open. Is this a 4.3 V6 or the old in-line 6?

 

[Scott06]

125 is a bit low but would expect it to run ok. might need valve work or rocker adjustment on the cylinder that is low whats the history on it

 

[SankorLiu]

The motor has been pulled from boat and the pressures are tested by without being run and the motor is still code. This is Mercruiser 165 Inline 6

 

[Scott06]

The motor has been pulled from boat and the pressures are tested by without being run and the motor is still code. This is Mercruiser 165 Inline 6

Get it up to temp and it will be higher. Given age of engine it likely sat so may need to free up some rings and valves once it gets going. May want to soak cylinders with marvel mystery oil and use merc pwoer tune or other top engine cleaner to get carbon out once it is running. Bottom line probably a good condition. Motor as long as nothing sticks