Marvel Mystery Oil

[sherpa]

A friend gave me a quart of Marvel Mystery Oil? I remember it from the 1960's but I have never used it. Where do you use it and what is it good for?

 

[groundcover]

As grandma would say " Good for what ails ya "!
have a friend that straight gassed her blower, over heated and shut down. Mixed some marvel in with 2 stroke gas and she's using the blower to this day .

 

[DJ54]

I use it in all of my old garden tractor engines from the 50's, 60's & 70's that were designed to run on leaded gas. Just a cap full when it came in the metal quart cans added to the gas, it lubricates and prevents exhaust valves from sticking. I also add it to the oil for the same reason, and to help keep internals clean.

I first used it back in the 70's in a Ford 1 ton truck w/6 cylinder. I'd asked the machinist who worked the head for me about Stellite valves, and he suggested using MMO. he used it in his racing bike at the strip. He's the one that told me it's great for the older engines designed to run on leaded gas, and it's upper cylinder lubrication properties.

What really made a believer out of me was when a neighbor girl had an older big box store riding mower with a B&S vertical shaft engine would stop running after an hour or so in hot weather but start back up after it cooled down. She called wanting me to come fix it. I just assumed it was vapor locking but when I tried to start it. it turned over very fast like no compression. I pulled the small cover off at the base of the valves and saw the exhaust valve was stuck open. Came back home and got my can of MMO. By the time I got back, the valve had freed itself. Replaced the cover and added a good capful of MMO to the gas and told her to run it and call me if it does it again. She called me 3 hours later pretty happy it never stopped on her the rest of the day. She then got her own can and added to the gas before mowing and never had any problems with it for the next 4-5 years running it. She done flat wore the mower out after that amount of time, so replaced it.

I use it mainly in older single cylinder air cooled engines but will add it to oil in new to me small farm tractors I collect/use to help clean things up and lubricate the upper cylinders. Gotta' believe it helps to free up/clean piston rings too. Some claim using detergent oil in older engines that has only had non-detergent oil ran in them since new will plug up the return ports. I've never personally had that problem.

With newer engines today and oils out there on the market, don't know that I'd use it in them. But it is great for older engines pre-unleaded gas.

 

[Gem99ultra]

I still use MMO. I add a splash to my oil every oil change in my '97 Chevy p/u to keep the lifters happy.
Sometimes oil 'fixes' are still the best.

 

[Captain Dirty]

Bicycle chains, throttle cables, anywhere a light, lubricating oil is desired. It doesn't seem to attract as much dust and gum up as crankcase lube oils do.

 

[dodge man]

I have a can on the shelf but wouldn’t use it in an engine. I’m not a big fan of products that make a lot of claims. I bought it because I found a home made recipe for gun cleaner and oil and it was one of the ingredients. It works great for that.

 

[Hughman]

I used it to winterize an inboard boat engine.

 

[John0829]

I do not normally go for snake oil products and considered MMO as one BUT it is definitely not snake oil. I now add it to every storage can of gas I have. I use Eagle Safety cans for my gas storage, they seal tight and have no worries about leakage during transport that happened occasionally with plastic containers. I keep about 50 gallons of gas on hand for the tractors, mowers, etc. and before I started adding MMO the gas would go bad. I had used MMO in the past for sticky valves as mentioned and since I had some on the shelf, that was getting pretty long in the tooth, decided to add it to the storage cans. Mainly to get rid of it. Best move I have ever made, have not had a can of ethanol laced stuff they call gas go bad since. I NEVER, at the end of season/use, run the carbs dry and leave the tanks full and even after some of the engines set for a year with the tank of gas they fire easily and run smoothly.

As an added bonus, that surprised me, I added some to the tank of my old 1992 GMC K3500 flatbed with a 7.4L for some valve noise and noticed that the gas mileage seemed like it was up. I keep meticulous records on all my vehicles pertaining to every drop of gas or oil added to them and after several tests running tanks of gas with and without MMO added it happened every time that the mileage was up by 1 to 2 miles per gallon with the MMO added. Doesn't sound like much but going from 10 mpg to just over 12 on that truck makes a worthwhile difference to me.

 

[5030]

I use it for air tool oil, won't gunk up air motors and it's less expensive than IR air tool oil.

 

[Gator6x4]

I use 2 ounces of white bottle Power Service and 4 ounces of Marvel Mystery Oil in every 5 gallons of road diesel fuel That I use in my 4 pieces of diesel equipment.