Marvel Mystery Oil - what do you use it for?

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IDoSeaDoo

Well-Known Member
Does Marvel Mystery Oil still have a place in the modern garage? what with synthetic oil and fuel injection, I'm not sure how or when I'll ever use my supply of it. I bought some to free up some seized pistons a long time ago and still have it laying around. Recently, I came into a gallon of the stuff. I own a new turbo-diesel truck and a lexus hybrid as well as a slew of jet skis and other small 2 and 4 stroke motors. What can it help me with?
 
Does Marvel Mystery Oil still have a place in the modern garage? what with synthetic oil and fuel injection, I'm not sure how or when I'll ever use my supply of it. I bought some to free up some seized pistons a long time ago and still have it laying around. Recently, I came into a gallon of the stuff. I own a new turbo-diesel truck and a lexus hybrid as well as a slew of jet skis and other small 2 and 4 stroke motors. What can it help me with?
I just use it to free up locked motors that have been sitting in fields for years, nothing else really, although transmission fluid works with that too. Although I could try it on some seized bolts but pb blaster and heat do it just fine.
 
Incense.

When I want my garage to smell like pepto bismol I light up my wifes potpouri candle and pour some MMO in the dish.
 
No self respecting garage or man cave should be without one of these.
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This is good stuff to use for pouring into the carbs to clean the top of the engine and loosen deposits. Lots of people used to d this way back when to keep their carbs clear. It is also good to put in the fuel to lubricate the top end. In our aircraft it is great to put into the fuel to keep the valves lubricated. Probably be good as a tapping or honing oil. I'll bet it is good for lubrication of air tools, and any place a light oil is needed or warranted. As you mentioned it is good for freeing up frozen or stuck devices. Good Stuff !!

Put it in your mower fuel, maybe a little in the engine bottom and just before you change the oil. Of course.... some people don't believe in it at all. A buddy of mine that has the same aircraft engine as me is fond of posting, "there are two types of Cessna 150 owners, those that have engine valve problems and those that use Marvel Mystery Oil."
 
how does it lubricate the valves? You mean like the valve stems/guides? Very interesting... I always thought oil lubricates that, but I guess not as the valve stem seal would prevent that...
 
Since MMO goes into the fuel it lubricates the top of the piston and the valve stems. I think is softens the deposits already there. Continental 0-200 engines are known for valves sticking. It isn't an approved additive for aircraft. It goes back to World War II. :) and there are mechanics today that learned from those guys. When I use it in my plane and I can tell the difference. Our engines were designed to use leaded fuel which is no longer available.
 
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100LL doesn't have enough lead for the Continental 0-200 that was designed to run 80/87 Octane leaded fuel which is no longer available.
 
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