Run the engine to warm it up, remove plugs (never test with plugs in or wires attached), install compression tester and turn over 4 or five times to get reading. Repeat for each cylinder.
The last time I tried a compression test was on my first car (which had an aluminum head) and I striped the spark plug well. Ouch! At least I learned a lot about engines after that. Has anyone ever heard of this problem occuring with outboard engines? It's been 18 years since that happened and I still cringe when I hear "compression test".
the compression test tool should have rubber orings so that you do not have to torque the fitting in as tight as a spark plug. No reason to torque the fitting in hard enough to strip anything. Ouch!
