1982 40 HP Mercury Compression

[thebubba]

Does anyone know what compression I should be getting from my 1982 40 hp Mercury Outboard? I am getting around 95 PSI from both cylinders, but I don't know if that is good or bad.. They are close in PSI to each other, but it seems a little low. Thanks for you help.

 

[guyjg]

That isn't bad for a 31 year old engine. My 2002 has 115 PSI on each cylinder.

 

[galamb]

Yes, I would be happy with 95 psi on an 81 model..

 

[thebubba]

Ok, I just wasn't sure if that was way low. Some of the mercury engines have 145 PSI, but I guess this model is lower. The engine looks brand new inside and out. I will continue my work of rebuilding the carb, replacing the impeller, changing the water jacket gaskets (they leak) and installing it on my 16" Alumacraft. Thank you for your responses.