Does anybody know what the engine cylinder compression should be in a 150/HP Evinrude V6 motor, and would the motor have to be warm to do a compression test?
Engine doesn't have to be warm but you get better results if it is.
A compression test done exactly as described in the Top Secret File should give you readings of 80-90psi or more. The important thing is that all cylinders fall into a 10-15% range.
If you can get the engine hot it gives more accurate numbers but as JB said either is fine, runit of coarse on a hose and ears and don't run the engine over 1500 rpm without a load on it.
