WHAT IS “GOOD” COMPRESSION?

[tiras_usa]

Hi,<br /><br />What should be the “good” compression for the used outboard?<br /><br />I’m trying to upgrade my boat with more powerful outboard but I don’t have money <br />for brand new outboard ….. they way to expensive.<br /><br />So I’m trying to buy used one (3 –4 years old) but when I asked the seller for the compression readings the told me that: “all cylinders around 125-128”.<br /><br />My old motor have 145-143, so should I spend $5K buying used engine with 125,<br />or this engine on his way to the junk yard already?<br /><br />Thanks,<br /><br />Alex

 

[DJ]

Re: WHAT IS “GOOD” COMPRESSION?

Those are good numbers. The important thing is that they are close to each other.

 

[JB]

Re: WHAT IS “GOOD” COMPRESSION?

Ditto DJ.<br /><br />"Good" compression is when all cylinders are close to the same psi. <br /><br />Big engines should read over 90psi and small, hand start engines should read over 60psi, but even those numbers depend a lot on the guage and the technique.<br /><br />Good luck.