compression test

[Meaux]

I want to check the compression on my two cylinder outboard motors. Should it be done with the untested cylinder plug in or out?? Should I get the proper reading on the gage with one pull on the starter rope or are multiple pulls necessary?<br /><br />Thanks for your answers<br /><br />Meaux

 

[Trent]

Re: compression test

Pull the plugs...All of them<br /><br />Rotate the crankshaft four to six turns per cylinder while checking. Your looking for 10 to 15 percent difference in all cylinders. Less than that you might have a problem.<br /><br />One other thing..Pull the saftey kill switch to ground out the spark to the cylinders. You dont want to blow the CDI pack if you have CDI ign.