85hp Johnson v4 Compression #'s ?

[FJ_Russo]

So I did the compression test as outlined above I have only had this motor for about a month and havent had a chance to put it in the water as there is about 8" of ice standing between me and it I was just wondering if these #'s sound good or about average for a 1975 85HP Johnson V4 engine.

Cylinder #1 115PSI
Cylinder #2 116PSI
Cylinder #3 119PSI
Cylinder #4 120PSI

Thanks for the info guys!

 

[ezmobee]

Re: 85hp Johnson v4 Compression #'s ?

Sound great to me. From what I understand, the actual numbers are not really that important as the testers aren't real accurate in that regard but they ARE consistant. Yours being over 100 and so closely matched is a very good thing.

 

[FJ_Russo]

Re: 85hp Johnson v4 Compression #'s ?

Thanks EZ! I was looking for factory #'s just out of curiousity but I coudn't find any.
So the Starmada does venture out into the world of Iboats. I thought we all just hung out there like a cult or something

 

[ezmobee]

Re: 85hp Johnson v4 Compression #'s ?

Nah, I'm just stalking you

 

[FJ_Russo]

Re: 85hp Johnson v4 Compression #'s ?

LOL Well I guess thats cool. I mean I always visioned my stalker being 120lbs blonde hair blue eyes and female but maybe we can work something out.... Your not far off that right EZ??

 

[boobie]

Re: 85hp Johnson v4 Compression #'s ?

There are no published factory #'s that I know of. As long as they are 15 psi with in each other should be okay. Last time I seen a spec published was in a 1967 Evinrude snowmobile service manual.

 

[FJ_Russo]

Re: 85hp Johnson v4 Compression #'s ?

ok well then looks like I'm good to go. I was Just do some routine checks and dreaming of spring. Thanks for the info Boobie!

 

[emdsapmgr]

Re: 85hp Johnson v4 Compression #'s ?

That engine when new probably had close to 125 lbs compression, so your current numbers are just fine. Also, it is not unusual for the compression to vary a few lbs from one head to the other, due to the way the blocks were machined at the factory. Looks normal!