compression test

Eazzy

Seaman
Joined
Sep 21, 2011
Messages
71
Can some ome explain the proper way to run a compression test on a 1996 Force 75 hp . Thanks
 

rick36

Seaman Apprentice
Joined
Apr 7, 2012
Messages
34
Re: compression test

Best to get a book and if you cant figure it out then ask questions :D
These guys dont like explaining basic things that are in the book but if you've got a problem they will help you ....
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: compression test

Pretty easy. Make sure your battery is fully charged. You don't want the motor to actually start so you have to disable the ignition system by engaging the "Kill Switch" by pulling the lanyard off of the Kill Switch. This will allow the starter to turn the motor over, but it won't start.

Pull the spark plugs out. Insert the compression tester into the spark plug hole and crank the motor over five or six times. Check the readings and proceed to the next cylinder. Some folks have indicated that you have to push the throttle to WOT to get a good reading. I've tried it with the throttle position at WOT and at idle with no affect on the compression readings. Readings should be within 10% from the highest reading cylinder to the lowest reading cylinder.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: compression test

Look in the Engine FAQs, Eazzy. good luck. :)
 

Eazzy

Seaman
Joined
Sep 21, 2011
Messages
71
Re: compression test

:pretty simple the way you explained it PNWBOAT borrowed the neighbors tester and had 115 117 118 on 3 cyl. 1996- 75 Force looks good to me. Will buy ya beer sometime, again thanks for taking the time. It was that happy face that helped JB. This is usually mine:facepalm:
 
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