Ever use Marvel Mystery oil? Why?

[Kira]

Just yesterday I looked into my lawn mower's tank and remembered when I used the stuff.

I used to add a bit of it to the fuel tank of OPE as I let the machine run out of gas for storage.
I figured a coating of lighter oil would be better than a coating of heavier oil.
Lately (last 30 years or so) I just use a touch of regular (5-30, whatever) oil.

ps. I put gas in my tank and squirted some down the old girl's throat and it fired up on the first pull.
What I need to do now is locate pure gas for my OPE.

 

[JavierH19]

No. Always thought it was like paint thinner or something similar so i never used it. Thought about using it once but I looked it up online and saw that it was mostly like pale oil or similar and mostly just snake oil.

 

[CB22]

I have used it in the past but not lately. I used it for the fuel not the oil. My main purpose was to lube the fuel pump, injectors and upper cylinders. I did seem to notice slightly better mpg when using it.

How about you all? Fuel, oil, both?

When I was a young guy, some old guy told me it's a magic juice that will fix all of my issues.

 

[GMBoy]

I place MMO and Seafoam in the same classification - old and outdated technology that serves no purpose in any modern car. There are just better alternatives today to spend or waste money on.

 

[demarpaint]

I just used some today. I mixed it 50/50 with TCW3 and fogged my snowblower with it, then changed the oil. I've done that over the years when I didn't feel like running around to buy fogging oil.

 

[SOUNDMAN5000]

I find MM Oil does serve a purpose and is far from Snake Oil when used with air cooled engines from my 97 Harley to all my lawn mowers.
I use a mix of Marvel and Sta-Bil and Ethanol free gas in every tank in my Harley's the last 25 years! Lucky, I have 100% pure gas at my local corner store.

25 years ago I ruined my stock carb with pure racing gas and that gas also swelled the o-ring in my Pingel petcock ( gas cutoff ) to the point it would not close or open. After replacing that carb , draining the racing gas and refilling with regular gas it was suggested I try a few oz of MMO in the gas to see if it would unstick my gas cutoff. IT WORKED after only a few miles! To this day 25 years later I can feel when I turn my gas on and off if I need to add a bit more MMO, the MMO makes the gas turnoff smooth as glass! So I am impressed as I can actually feel what MMO does to a rubber seal or O-ring so it MUST be good for all the other rubber parts in a fuel system? I think so....

The mixing MMO with Sta-Bil came by trial and error but in my old Harley I get a bit more snap in the exhaust note and general feel of the bike when mixing MMO and Sta-Bil. Who knows why but I do...

My old Harley now has that same carb with out a rebuild over 25 years now. I do keep the tank 100% full and the gas may sit 8 months and one time the gas sat almost 2 years! I did drain the 2 year gas but my old bike still runs great and zero rust in the tank thats to MMO and Sta-Bil!

I use the same MMO and Sta-Bil mix in all my lawn gear and never had an issue and my lawnmowers are old and sit every winter.

Over 30 years ago, I knew a large industrial machine shop maintenance mechanic that maintained many huge machine lathe and he would mix MMO with the gear oil used in those large machines. I don't remember the specifics but he would swear the MMO made a huge difference to the gears with long term heavy 24/7 use.

I don't use MMO so much in my new cars and such but anything old or small engine, air cooled, I love the stuff!

 

[kschachn]

Sounds amazing.

 

[DweezilAZ]

I'm all in. Ampco oiler installed in '63 Plymouth Valiant. Every tank in an '86 Olds and 05 Saturn.

 

[nomas]

About 25 yrs ago we were doing maintenance on some two cylinder air compressors in some high voltage circuit breakers . Very humid environment so there was a lot of water in the crankcase . My genius Supervisor told us to drain the oil and then add a half a quart or so of MMO . Run it until the oil got hot ( It never did ) then drain and refill with compressor oil . It did NOTHING to clean the sludge from the crankcase .

 

[Jackson_Slugger]

I place MMO and Seafoam in the same classification - old and outdated technology that serves no purpose in any modern car. There are just better alternatives today to spend or waste money on.

I don't think so. I'm not fond of Seafoam because it's mainly coming from use on old boat engines but Marvel was always mainly automotive applications. It's ingredients are still useful in limited applications though I agree in general it's not needed in modern OEM engines using Top Tier gas.

But it's a good mild fuel system cleaner/additive on maybe older cars using non-TT gas. In fact I might start putting it in my father's Vulcan Ford Taurus because he isn't driving it and I only occasionally take it out for work just to run it. It's also very good for small engines...

 

[BigJohn]

I just purchased a 1997 Jeep Wrangler 2.5L Four Cylinder and I am going to run some in a tank of gas. The fuel gauge isn't acting properly and at the least, I hope it straightens up. Not sure what else it will do, but giving it a try.

I'll report back.

........

 

[Slow Car Sport Mode]

Funny how when someone questions ingredients in certain motor oils or other automotive liquids: majority of BITOG members say to look at overall performance instead of hair splitting the ingredients.
But when MMO is being evaluated for its performance - suddenly all results claimed to be one's imagination, because there is no way MMO ingredients could achieve such results.
Double standards at best, it seems.

Coulda sworn I read on here on an OLD thread like 2006 or so (before my time) that MMO is denatured kerosene dyed red (MOST of it. The majority of the bottle)

 

[Slow Car Sport Mode]

It seems to have gone up in pricing at Walmart, today I was there briefly to grab a wiper and drop off used oil. It's approaching $6 a qt. which seems higher than it's usefulness in OPE. Berryman B-12 is still $2.97 at Amazon...

Yeah it has.

The cans of R-134a are larger now (?) and also $8.88 per, used to be $5. I used to have about 40 of them, in a stash. no more....

MMO has gone up

Only the Supertech 5000 mile has a price that resembles what it was, if the 6 quart boxes don't knock off the 5 quart jugs.

This change is real, we are here folks...

 

[nomas]

It is composed primarily of petroleum distillates, including mineral oil (60–100%), mineral spirits (10–30%), tricresyl phosphate (an antiwear and extreme pressure additive in lubricants, 0.1–1.0%), ortho-dichlorobenzene (a softening and removing agent for carbon-based contamination on metal surfaces, 0.1–1.0%), and para-dichlorobenzene (a precursor used in the production of chemically and thermally resistant polymers, <0.1%).

 

[BigJohn]

Ok... its been three days with MMO in the fuel and the sump. The engine does feel as if it has a little more kick, but that is not the reason I am running it. I want it to mop up and clean up all the crevasses and corners of the fuel system and the engine. There are ZERO negative issues with it running and performing so far.

 

[GR_CoB]

Ok... its been three days with MMO in the fuel and the sump. The engine does feel as if it has a little more kick, but that is not the reason I am running it. I want it to mop up and clean up all the crevasses and corners of the fuel system and the engine. There are ZERO negative issues with it running and performing so far.

Let's see how long it takes for the naysayers (who never tried it in a neglected/old/tired vehicle or carbureted engine) to come in and proclaim that you are wrong and any positive results are a placebo effect.

 

[K-Man]

I suspect it might be useful to lube in-tank fuel pumps when added while filling the tank with fuel. The stuff contains a solvent and does have its uses, though I doubt it would have much benefot in a new car.

 

[GR_CoB]

I do have a recent fail story about Marvel Mystery Oil. Got a new-to-me scooter. 2009 Tomos Nitro 150cc. Exact copy of the one in picture below, just with a helmet/storage box on the rear rack. Runs great, gets 85MPG, but fuel gauge is iffy. It works correctly for first 10-15 miles after fill-up, and after that it's just all over the place. So I am forced to guess my fuel level by miles driven on odometer. Added an ounce of MMO in fuel at recent fill-up, and MMO didn't fix the fuel gauge. Fail. Unacceptable. MMO bad.

Ok, now that I'm done mocking the naysayers and their testing procedures - yes, all above is true, except for my attitude about it. I'll keep using MMO because engine is noticeably smoother with it in the fuel tank. If it somehow brings the fuel gauge to life - great. If not - I'll eventually find a replacement. Until then I'll keep enjoying this little Slovenian scooter. They definitely did a great job on taking a basic Chinese scooter and refining it from ground up to actually enjoyable, comfortable, and reliable machine.

 

[BigJohn]

Ok... its been three days with MMO in the fuel and the sump. The engine does feel as if it has a little more kick, but that is not the reason I am running it. I want it to mop up and clean up all the crevasses and corners of the fuel system and the engine. There are ZERO negative issues with it running and performing so far.

Well.... I had a surprise "BINGO" yesterday evening on the drive to the Mexican Food joint for dinner...... "Bingo" the low fuel light and the distinct-ant "DING" happened. No telling how many years that has been off-line in the '97 Wrangler.

That is WIN #1 for MMO....... for me and the Wrangler.


............

 

[Dodgetracker]

Just ran it in wife’s 2004 wrangler in fuel and sump for the last 150 miles before changing oil. I’m told the ticking noise is from cam position sensor (I think is what was said) it did quiet that down a lot. Jeep runs real good for 150000+ miles.