Marvel Mystery Oil Vs. Fogging Spray

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Another way to easily fog an inboard engine with a fuel water seperator filter is to pour several oz of 2 cycle oil in the new fuel filter and then run the engine a minute or two. It will coat the entire system. You will se the smoke as evidence.
 
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Well, I actually had some fogging spray, Mercruiser brand, left over so I used that. That stuff was more like foam spray than oil. Yes, it was thicker and I was wrong about that.
 
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Motor oil is fine, I have used it for years before you could buy fogging oil. Recommended by Merc and OMC in their manuals..
Originally Posted By: demarpaint
Originally Posted By: Mike66
I just slowly pour a bottle of any 30w down the carbs in my 454 Crusaders until the engine coughs, then flood it out with a quick pour. Works fine and it's cheap and easy. Engines start just fine in the spring.And no, I haven't torn down the engines to see how they really are. I also think it's helpful to plug the exhausts and carbs to prevent moist air flow through the engine, which can condense and form rust.
I would not use an engine oil as a fogging oil, the additives could cause problems when poured into a running engine to fog it. TCW-3, MMO, or fogging oil are better much better choices.
 
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would not use an engine oil as a fogging oil, the additives could cause problems when poured into a running engine to fog it. I read a Mercruiser owner's manual for a newer boat, it said the other choice than Merc's fogging oil is 20W engine oil.
 
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Originally Posted By: ledslinger
would not use an engine oil as a fogging oil, the additives could cause problems when poured into a running engine to fog it. I read a Mercruiser owner's manual for a newer boat, it said the other choice than Merc's fogging oil is 20W engine oil.
what problems would the additives cause?
 
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Bluestream, the ideal storage/fogging oil is one that is: 1) Easily distributed 2) Leaves a coating on metal surfaces to protect them from corrosion 3) Will burn off cleanly when the engine is started. MMO is just about ideal for this application ... followed by a TCW-3 2-stroke oil (low/no metallic additives). Engine oils are specifically formulated not to burn off easily and they have some metallic additives (moly, zinc, phosphorous, etc ....) which could foul-up emissions equipment, sensors, spark plugs, etc ... Sounds like you have been getting away with it to date OK ... but as others have said, there are better products for this application ... and they don't cost much more.
 
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With butane, propane and naptha, I just don't see how that would protect an engine during storage.
Butane and propane are for the propellants in the can. Naptha is for creeping and penetrating.
 
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My father always dribbled Rislone down the carb at idle until it started smoking and/or squealing, then shut it down. Pull the plugs in the spring, crank to blow out the extra oil and prime the carb, either put in new plugs or wipe the oil off them then reinstall, and the engines would fire right up (Mercruiser 454 inboards, 1300 hours, 24 years old, still running beautifully, been fogged like this every winter).
 
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