compression

[donaldandbobbi]

Looking at buying 1986 johnson 8hp. Checked compression and both cylinders were at 100. Just wanted to know if this is about right for a motor of this size and age. Motor runs but dies shortly afterward. I suspect the carburator is dirty do to it sitting up. Also would like to know what octane fuel and oil mixture is reccommended for this motor.

 

[steelespike]

Re: compression

100 lbs is fine its good that it is even between cylinders.87 octane at 50:1 mix.Use TCW3 rated oil.if you don't know the history you should consider changing the impeller.

 

[KYHunter2]

Re: compression

Might as well do the carb while your at it. Soak the carb and blow out with compressed air. I use the computer air in a can works well.