Re: Top speed with 18hp Evinrude on 14′ aluminum

[David Stanton]

I had a cheapie compression gauge a few years back that had the check valve at the far end of the rubber hose (the cylinder end), so unless you were measuring a big cylinder, like in a big car engine, the volume of space in the hose between the checkvalve and the gauge offset the readings down significantly. Be sure you don’t have that problem. I tossed that one out.