OB compession

[Ron Brassord]

I am having a problem with plugs fouling on my 1982 6 hp johnson. A compression test[cold] shows about 75 pounds, each cylinder. . Anyone know what it should be? Engine is old but has less than 200 hours. I am trying a 100-1 mixture rather than 50-1---can this do damage? The fouling is a black greasy coating that kills the engine in 3/4 hours. Any ideas? It works hard pushing a 23 Sea Sprite. Thanks Ron B LHP FL



rdbrass@aol.com

[Nick Mediatore]

I am having a problem with plugs fouling on my 1982 6 hp johnson. A compression test[cold] shows about 75 pounds, each cylinder. . Anyone know what it should be? Engine is old but has less than 200 hours. I am trying a 100-1 mixture rather than 50-1---can this do damage? The fouling is a black greasy coating that kills the engine in 3/4 hours. Any ideas? It works hard pushing a 23 Sea Sprite. Thanks Ron B LHP FL

Stick to the 50-1 oil ratio, otherwise you are certain to have serious engine damage. Check to see that you are using the factory specified spark plugs; if they're the right plugs, go to the next hotter plug.

Chances are an engine that old with so little use has stuck or sticking piston rings because it wasn't properly serviced before being stored away or was left in a damp environment. The right plugs should solve the fouling problem, and with a little luck, five or ten hours of use will unstick the rings and the fouling problem will end.

I am using an engine that also laid about for a long time unused and though it didn't foul the plugs it ran very poorly. The more I run it, the better it runs.

Whatever you do, stick to the 50-1 oil ratio or that engine will be scrap iron.



nmediatore@aol.com

[Ed Roberts]

I had an '86 6 hp Evinrude that came with instructions to use 100:1. But shortly thereafter the dealer told me that it had been found that 100:1 left insufficient oil on the bearings, and that OMC had changed their recommendation back to 50:1.

OMC sells some "snake oil" called Engine Tuner that is squirted into the intake with the engine running, or with severe stuck rings is allowed to soak the rings. Claims to "Clean out gum, varnish, lacquer, and removes carbon from sticky rings." Seems to be good.

Good luck, Ed R.