88 Johnson v6150 compression check

[runner383]

I have a 88 johnson v6150 I did a compression check on all cylinders they all read 90 is this a good compression? how low before it needs rebuilt? Thanks...

 

[joereeves]

I assume you're saying that the engine is a 1988 150hp V6 Johnson. The compression is usually about 95 on the starboard bank and slightly less on the port bank. It normally does vary somewhat from gauge to gauge. You're in the "good" ballpark.

If you suddenly find a cylinder dropping to somewhere in the 70's or low 80's.... now, there's a problem.

 

[runner383]

Thanks for the info....