Used Seafoam and what a difference

[Mucho_MPG]

Got some directions from the net on how to "decarb" my 73 Johnson 25HP outboard. Mixed 3/4 gallon with a full 16oz can of Sea Foam and some 50:1 oil and fired her up. Holy [censored], the smoke filled the entire neighborhood. After about five minutes out of the exhaust came a bunch of oozing brown pudding like carbon in my splash tank. I ran it for about 45 minutes and the carbon just came melting out. The Seafoam really cut down on the vibration and the noise of the engine. I then took "Deep Creep" and shot that directly into the carb until it died. Then I let it sit an hour and came back and started it. Even more smoke and carbon!

Very happy with the results and will be doing this once a year. Seafoam is great stuff! Scary to think how much carbon accumulated in this engine over 30 plus years.

 

[verolla]

Hi there

One other thing you can do in addtion to spray the carbs with deep creep is spray a bottle of deep creep into the sparkplug holes. First take out sprak plugs spray a can of deep creep in all the spark plug holes equally. Put spark plugs back in and let sit over night next day used compress air and blow out the spark plug holes. put spark plugs back in and run engine. Make sure the engine is horizontal to allow the deep creep to keep in contact with the pistons. I am gonna sea foam my boat soon and will probably decarb by this method.

 

[Mucho_MPG]

Hi,

Thanks for the tip. I'll pop off the plugs and shoot some in there.

After i shut the engine off and left for a few hours, underneath the outboard, there was still the carbon oozing out of the exhaust and hitting the ground.