Anything wrong with a 1975 85hp Evinrude?

[smyto]

Re: Anything wrong with a 1975 85hp Evinrude?

I hope its the adapter because those readings are low. See if you can get e proper adapter or guage to get proper readings. Good luck!

 

[jasper60103]

Re: Anything wrong with a 1975 85hp Evinrude?

FWIW, I was using this Compression test Kit. It only comes with 14mm and 18mm adapters. I was using the 14mm one.

OEM #27138
https://www.bosstoolsupply.com/index.asp?PageAction=VIEWPROD&ProdID=11811

 

[smyto]

Re: Anything wrong with a 1975 85hp Evinrude?

If it didn't fit properly (as in fit as good as a plug) you will probably not get a proper result. I suggest you find one that fits right. If the motor has proper compression, it IS WORTH SAVING!! The other stuff is easy to fix, bad compression is not. A proper compression reading is the answer to this thread.

 

[smyto]

Re: Anything wrong with a 1975 85hp Evinrude?

OK, I'm back.

Update. I verified all wires have spark. Thanks to my son for watching as I turned the ignition.

I'll buy a micrometer tomorrow to measure my spark plug diameter to determine the adapter size needed for the compression tester guage. Unless someone can look it up for me? I don't have a shop manual.

thanks,
jasper

I see you have plans to do this. Sorry for telling you to do something you planned on already!!:redface:

 

[Sea18Horse]

Re: Anything wrong with a 1975 85hp Evinrude?

The readings shouldn't wobble. They should climb in steps with each revolution. And level off at some value. If they jump up and bleed off between revolutions then the tester is defective. Either the schrader valve is bad in the adapter or in the gauge. (Or they gave you a Mazda rotary tester by mistake!)

Cheers......................Todd

 

[wattsbar]

Re: Anything wrong with a 1975 85hp Evinrude?

new to the forums,but ive had a 76 85hp for 4 years, had a couple mercurys during that time also. mercurys are gone but my evinrude is still going strong. its been used every year since new,if youre compression is good dont give up on it, with proper maintenance over the years my lowest compression is 115. good luck!

 

[jasper60103]

Re: Anything wrong with a 1975 85hp Evinrude?

Yea, I'm a little ticked now.
I went out and tried again, and got similar results.
I'm sure the adapter
was seated firmly in the plug socket.

I'm gonna get another tester in the morning.

Stay tuned, and thanks everyone for your support.

jasper

 

[iwombat]

Re: Anything wrong with a 1975 85hp Evinrude?

Like was said before - the needle shouldn't wobble at all. There's a one-way valve (and a release) air goes in, and shouldn't come out until the release button is pushed.

Even with a defective gauge and hokey readings, that those numbers are close is very encouraging. Keep charging ahead with the tests.