Evinrude Compression

[mjash]

I just purchased a 77 evinrude 85hp. I am able to turn the flywheel by hand with all plugs in. I am having a hard time believing that there is no compression in any cylinder. am i crazy?<br /><br /><br />Any help is appreciated.<br />Mark

 

[WillyBWright]

Re: Evinrude Compression

Welcome to iboats. <br /><br />It's not unusual. The rings are designed to seal better with a load. They're still pretty relaxed at hand cranking speeds. The only way to know for sure if you have good compression is with a gauge and a healthy battery to crank it over.

 

[ob15]

Re: Evinrude Compression

Mark, I have a 1980 & 1989 50hp & can turn both over by hand no problem.

 

[CATransplant]

Re: Evinrude Compression

One caution about turning flywheels by hand: If you're going to do this, pull the sparkplug wires. Every time!<br /><br />A starter ring gear can do some serious damage to your hands if the engine starts.

 

[papa_Lazerous]

Re: Evinrude Compression

Valid comment there CATransplant i know someone who was working on a small engine and it had a liberal amount of WD40 in on and around it to help loosen some bolts, although no fuel connected It fired for a second and although did no harm made my mate jump and nearly have a heart attack. And I can turn my engine over easily enough by hand, i can feel resistance but the compression is allot stronger when cranking. also if the engine has been standing the rings may be a little gummed up and stuck so to give the impression of no compression, after a good run they would free up if this is the case