1993 evenrude 70 hp compression

[adamjenzerr]

I was changing my plugs today and noticed a bit of oil on the plugs. I did a compression test and the results are
top cylinder 90
middle is 65
bottom is 90
Advise?

It runs great

 

[flyingscott]

that's pretty common for the middle cylinder to be damaged on those. There was a service bulletin for the peehole to be re located to the top of the block to prevent that. Is that Done? try a different gauge, or pull the head off

 

[adamjenzerr]

I just moved the pee hole last week which I assume was too late.
What do you mean try a different gauge?

 

[flyingscott]

get a different compression tester and try again

 

[adamjenzerr]

ya did that lol

 

[adamjenzerr]

get a different compression tester and try again

I guess i need to rebuild?

 

[racerone]

As stated very common for #2 to be KAPUT.----The service bulletin came out in 1994 to move the telltale.-----But these motors are good and rarely need to visit the Evinrude hospital I think.

 

[flyingscott]

Check the piston size before anything.

 

[adamjenzerr]

How does one check piston size

 

[flyingscott]

When the head comes off you can see it. It will be on the piston either a part# and or size. May need to clean the pistons off to see it