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My Plugs Keep Fouling

J

Joe P.

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" I have a 1979 Evinrude, 15 h

" I have a 1979 Evinrude, 15 horsepower, that I use for Duck Hunting. When returning from the trip before last the engine was running at about half speed. Once on shore I discovered that the spark plugs were fouled. I replaced the plugs, ran the engine for about 30 minutes and it worked fine. The next day the engine ran fine on the way out but again, when returning, the engine ran at half speed. When I removed the plugs they were fouled.

Any idea as to what is causing the fouling? "
 
" Sparky,

I was told by my


" Sparky,

I was told by my local marina to use 8ozs. of oil for every gallon of gasoline.

After reading a shop manual that I purchased yesterday, I discovered that the proper fuel/oil mixture is 16 ozs. of oil for 6 gallons of gasoline. I have to believe the manual is correct. Therefore, I think my fuel mixture is excessively rich. However, being new at this, I am somewhat confussed. Any help you can provide is appreciated. Thanks. "
 
50:1 is the mixture ( TC

50:1 is the mixture ( TCW-3 ) . Thermostat must be installed to prevent motor from running cold.
 
" sparky,

I have OMC oil th


" sparky,

I have OMC oil that meets TCW-3 but as I mentioned eairler, I believe I am using too much oil. I am going to put 8oz. of oil into a 3 gallon tank and give it a try in the morning.

If the plugs still foul I will look into the thermostat. What do you think? "
 
" Joe,
I feel sure that you h


" Joe,
I feel sure that you have found your problem. To much oil. 50:1 is the standard mix. I know some people that only do trolling, that will use as much as 100:1. I've used 75:1 when I use to troll for Salmon, and did it all day at low RPM's.

Change the mix, clean the plugs, and I think you will be fine.

Gerald K4NHN "
 
" Gerald,

I agree with you.


" Gerald,

I agree with you. I have changed the plugs and put in the correct amount of oil for a 50:1 mix. My only problem now is that the bay is frozen (I am in Southern New Jersey)and I have not had the opportunity to go out again. Thanks for your help.

JoeP "
 
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