COMPRESSION Check

[sbb03]

I checked the compression on m

I checked the compression on my 78 merc 70 and I got 100 on all cyl.What should it be? I was using gauge that has the rubber on end that you hold to hole are they acurrate? Do you remove all plugs before you do test or remove one at a time?

 

[brentle]

Steve it makes no difference i

Steve it makes no difference if you have all plugs out or one at a time but its best to check when engine is cold and usually with the throttle wide open which of course is hard to do when the engine will not turn over with throttle in WOT position. 100 per cyl is good for a 78 model. usually only get concerned if there is a difference between 15-20 across all cylinders.

 

[ikia]

Throttle position on a 2 strok

Throttle position on a 2 stroke has no effect on a compression test.None.