1966 6 hp fisherman Evinrude problem with power

[patflans]

1966 6hp fisherman

Hi all! I am really confused, I bought 2 years ago from the original a 1966 6hp Evinrude fisherman motor. I use it for moose hunting to get to the island, about 6 min and once a year for fishing during a weekend. My issue is, it seems to fall on one cylinder, I did a compression test and in both cylinders I have 80psi. I did a spak test with the spark tester and the light comes on on both cylinders. What am I missing?

 

[patflans]

Hi all! I am really confused, I bought 2 years ago from the original a 1966 6hp Evinrude fisherman motor. I use it for moose hunting to get to the island, about 6 min and once a year for fishing during a weekend. My issue is, it seems to fall on one cylinder, I did a compression test and in both cylinders I have 80psi. I did a spak test with the spark tester and the light comes on on both cylinders. What am I missing?

 

[racerone]

Very common to run on one cylinder.----Answer this question.-----Does the spark jump a gap of 1/4" or more , yes or no ?.------Or remove the flywheel and you will likely find 2 cracked coils.-----Luck if they have been replaced already.

 

[oldboat1]

Is the fuel fresh? Try the drop-cylinder test: Start the motor and remove one plug boot at a time. If there is no effect when one of the boots is pulled, that plug is probably not firing.

 

[F_R]

I don't care what the spark tester says, pull the flywheel and take a looksee. Dirty breaker points?? Cracked coils?? Bad plug wire??

 

[Crosbyman]

my latest fix on a 4hp was a bad connection inside the plug's rubber booth

due to corrosion the spike inside the booth was not making good contact

if all is ok under the flywheel (points cleaned- adjusted condensers ok and coils …. check the wires

you may have just a bad sparkplug ..they do go bad

 

[JohnnyGuy]

Also pull and check plugs, are they fouled? Sounds obvious, but worth mentioning.

A nice cheap spark gap tester is Lisle 50850.
I had purchased the inline one that lights up as you described originally. Now it just sits in the bottom of my toolbox.

 

[Mohawkmtrs]

...or you can go to an auto parts place (NAPA, etc.) and pick one up for about $8-$10.