Compression Question?

[Dm82]

Hello again:
So yesterday I tested the compression of my 68 Johnson 100 hp. Results as follows:

Cyl. 1: 119
Cyl. 2: 117
Cyl. 3: 122
Cyl. 4: 119

So are these good numbers. I know that them being that close is good but I thought that they should be higher. If someone could clear this up for me I would appreciate it thanks.

 

[HybridMX6]

Re: Compression Question?

They sem good to me. Different gauges give different readings. Some read high, some read low, so since the #'s are in the 100's for each and so close together, I'd say she's good to go. My 1993 60hp had 115psi, and I've heard of larger V4's or bigger motors even having 90's.

 

[Dm82]

Re: Compression Question?

Thanks for the reply. I just wanted to check with someone who knows a little more about boats than myself. Thanks again.

 

[kenmyfam]

Re: Compression Question?

Look good to me. As said different gauges will give different results. Even within 10% and over 100lb you are just fine.