First time winterizing - Engine Fogging question

badrano

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Aug 7, 2018
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I'm going through my first winterization. From the many posts I've read, I feel lucky that I can get to all sides of the engine fairly easily....just have to remove the back seat bulkhead which is just dozen screws.

I got through all the filter changes and oil changes and next in line was to fog the engine. I removed the flame arrestor and started the engine. I went to spray the fog in to the carb and the engine did not stumble nor did I see smoke coming out of the exhaust. I sprayed right in to the butterfly valves and nothing. I also wasn't looking at the exhaust and maybe I was expecting a big cloud of smoke.

Maybe there is mixed opinions about this, but the instructions on the fogging oil say to remove the spark plugs and spray in to the cylinders and crank the engine a few turns. I have not done this.

I may have jumped the gun after this step and drained the block and filled with AF. So I don't know if I'm ok, or do I need to buy some more AF and do a do-over of the fogging.

Thanks.
 

alldodge

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If you shut the motor down during the time your spraying the fog oil in, your good. If you sprayed oil in and let it continue to run, then the oil was burned off and there is none left. That said, you should be fine without the oil. To go the extra step, pull plugs and spray a little oil in each cylinder and do not crank. Then reinstall the plugs
 

badrano

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Thanks AllDodge.

I did not shut it down while spraying the oil. Is there supposed to be an obvious big cloud of smoke?

I'll pull the plugs. At least I'll get to see what shape they are in. There's nothing in the previous owners records about any plug replacements, just rotor and cap. The engine has run great since I bought the boat.
 

alldodge

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I did not shut it down while spraying the oil. Is there supposed to be an obvious big cloud of smoke?

That depends on the amount of oil the can will push out. If the fogging oil puts it out at a small amount, then the motor will not bog down. If the oil comes out heavy, which is best for fogging, then the motor will dies when being sprayed, good fog.
 

tpenfield

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I could never get my old carb'ed 454 Merc to 'die' with the fogging oil. . . I even used 2 cans of the stuff and sprayed them simultaneously. The only way I could get the engine to choke on the stuff was to pour a bit of motor oil down the carb as well.
 

JoLin

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I use Marvel Mystery Oil. After I've given the engine a good flsh with fersh water (on muffs) I replace the fuel-water separator and fill the new one 3/4 way with MMO. Start the engine, let it run 20-30 seconds, then pour MMO down the carb throat until it stalls. Don't know if it works better or worse than any other method, but it's easy and makes me feel better. Only costs a few bucks to do both engines, too.
 

kulle

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May 23, 2018
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I could not get mine to stall, almost though, and a big puff of smoke cam out exhaust - I feel I got enough oil in there. I just shut it down when it hit the almost stall point, then put a little fog oil into each spark plug cylinder area and closed it up.
 

HT32BSX115

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Dec 8, 2005
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My last boat was a 1966 model, and the hr meter failed in the 80's at 1500+hrs, and the engine was NEVER fogged over winters.

I finally sold it in 2005. In the 39 years that I operated it, it never seemed to matter that is wasn't "fogged"

I am thinking fogging might help the people that sell the fogging oil more than it helps the people buying it.
 

H20Rat

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Mar 8, 2009
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I have never once fogged any of my 4 stroke engines, and I can say I've had a lot of different 4 strokes over the years. I've never had a 4 stroke engine fail on me, period. (2 strokes on the other hand, those are finicky...)
 
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