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This is a question on the maintenance of outboard trolling motors. What is the standard practice (if any) for decarbonizing outboard motors? Whether 2 or 4 cycle, outboards can have many hours of slow speed trolling. I would expect that a carbon build up could occur in the engine and this could lead to poor performance of the motor. Has anybody done anything in the way of maintenance to prevent or eliminate a carbon build up in the engine? I presently use premium ethanol free gas with a fuel stabilizer and change the spark plugs regularly to minimize any engine problems.
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Hey BW
I have a Mercury 40hp 4stroke that came with my used Legend in 2006. The motor is a 2000.
It is used mostly for trolling and I have not done anything different than what you have done.
The motor runs just fine. I had a problem this Summer, but I eventually tracked it down to a bad spark plug. I had replaced the plugs 3 years ago and for some reason, one went bad.
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I guess your routine will depend upon whether your trolling motor is also your main/only motor. Often your run out to the "fishing grounds" (10 minutes) will do a lot to clean your motor. If not then a GOOD run across the bay and back (20 - 30 minutes) every so often is a great solution.
Our trolling motors (kickers) should also run at higher rpm occasionally to clean them, .... but we don't! Big motor out, troll motor down = putt, putt..., and back in with the big motor. It's like going to the gym for us. Hard to establish the routine, but sure pays off! (They say anything you do 14 days in a row is a "habit"! -- appropriate thoughts only here, please!)
Plugs, ....change them annually as part of your spring prep. For the cost of a/couple/few plug(s), just change them as part of your regular maintenance. Depending on your fall prep routine, you may want to change them after the first startup/run in the spring; oiled cylinders after the winter may foul your plugs, so change them after you've run the motor. And then, good to go....!
Next week: When is it too soon to lift the cowling on a Merc and shoot it?! Or, "Saying good bye to a NEW friend." LOL!!!!!! ("I'm going to burn for that one...!")
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One of the greatest mechanics of all time told me he would remove the air cleaner(not an issue with most if any out boards) and spritz water through the engine when it was hot for a couple minutes before he would tear it down and the insides would literally be steam cleaned and have zero carbon. He is a mechanic of 40 years plus and never had a spec of grease on his person or in his Bay.
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Hi All; Thanks to all of you for your comments. My outboard is my only motor (no kicker) and is used for trolling and for high speed travelling to and from various fishing locations so it is not solely used for trolling. Generally, it does get high speed WOT (wide open throttle) runs each time that I'm out and I'm guessing that those runs help minimize carbon build up. I find the comment about water spritzing interesting and will check that out further.
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Quicksilver Power Tune Internal Engine Cleaner. Quicksilver Power Tune is used to remove performance-robbing carbon build-up from the combustion chamber. This engine cleaner can be used in all 2- and 4-cycle carbureted and fuel-injected gasoline engines.
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I have an 8hp merc 4 stroke. All I do is run full out for few minutes before I use the big engine to move to next spot. I haven't had a problem doing this. Starts great every time.
Outboard Motor Maintenance, Decarbonizing
