Compression test result question

[H2Odog]

I have a 96 johnson 50hp. I did a compression check on it today and found the top cylinder at 145psi and bottom at 110. I read they should be within 10% of each other. Honestly I thought the top cylinder was high. Any thoughts or remedies? The reason I did a compression check was I am trying to sell the boat. Other than that it runs great.

 

[javsam]

Re: Compression test result question

the engine should have been warmed up to operating temp, prior to taking compression test and when taking test best to have throttle wide open.also battery should be fully charged before test.<br />javsam

 

[reeldutch]

Re: Compression test result question

i suggest a good decarb.<br />may be 2 or 3 times if you have never done it.