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I am leaning towards using MMO in the next oil change on my lawn mower and other small engine powered equipment. The mower is at least 15 years old and smells of burning oil when in use, not hideously so, there is no blue smoke, but there is an oil aroma. I've got other equipment that is as old or older that I need to service for the winter too.

I've seen a youtube vid that used MMO to clean out a lawnmower that had not had service in a very long time to clean out the sludge and nasties that would have surely been there. I've seen this guy use it to clean out a 389. The thing is, he didn't really get into what it does, though he did say that once he got the engine cleaned out he would be using royal purple in it.

So anyway, does anyone know anything about MMO and whether it should be used only to clean out an engine then replaced with straight oil or to use it as part of the normal oil change/service of an engine. At the moment I'm only interested in using it in small engines, but any experience using it would be greatly appreciated.

PUT IT IN WITH YOUR OIL ON HIGH MILEAGE MOTORS helps really keep lubed and voats the rings helps to greatly prolong high use gas engines.

Fpr cleaning valves and carbon deposits i use transmissoin fluid poured straight down the carb or throttle body til the motor cuts off let sit overnite then crank next day let run til it stops smoking and your good too go.DON

THUNDERSTRIKE1 wrote:
Fpr cleaning valves and carbon deposits i use transmissoin fluid poured straight down the carb or throttle body til the motor cuts off let sit overnite then crank next day let run til it stops smoking and your good too go.DON

The ford dealership used to sell a fluid that instructed you to do the same thing, basically hydro locking the engine and letting it sit. It worked....but damn that is just not something i would want to do with my connecting rods! They smoked for miles too!

This method just choke the engine off,then penetrates deposits and burns off when crak it up.This has been done by me since my grandad tought me and every car ive owned has gotten over 250,000 miles then was sold to someone else whoom is still driving them today.Don

Sea Foam is the most popular product to do what you guys are talking about.

Now with the Marvel Mystery Oil I remember my father using it all the time back in the day. Heres the link to their site which gives you an idea of it's purpose: http://www.marvelmysteryoil.com/index.php/site/mmo/

Thanks for the link LG, I have avoided company literature because of course they're going to say it does all sorts of marvelous things. I would prefer real world experiences. If I decide to go through with it, then I'll check out the company site for info and tips.

I'm leaning more and more to trying it, it's only $5 and I'd be able to do several small engines with it if I want to.

Lowgear wrote:Sea Foam is the most popular product to do what you guys are talking about.

Now with the Marvel Mystery Oil I remember my father using it all the time back in the day. Heres the link to their site which gives you an idea of it's purpose: http://www.marvelmysteryoil.com/index.php/site/mmo/

+1 to recommend Seafoam.

The only thing I can add is that if marvel mystery oil provides some additional sealing capability in the rings, definitely use it.

If you are concerned with sludge and deposits and your mower and other small equipment and is 15 yrs old or less, you are probably fine unless someone specifically ran straight 30w oil in it. Any standard multi-viscosity oil since I dunno...maybe early eighties? will have enough detergents and refinement that you shouldn't need to worry about sludge. Of all the engines I have disassembled over the years, it's only been the very old engines that have been sludged beyond belief with early EGR systems, or run on straight 30w, which pretty much turns into black wax after awhile.

with the price of small engines these days, your best return on investment in time and money is regular oil changes and plug changes until they throw a rod or turn into oil crop dusters.

Bear in mind 15 yrs of reasonable use on agricultural/lawn equipment is pretty darn good and near the end of it's life cycle.

Briggs still recommends straight 30, but it is detergent oil.
Kohler is 10w30

I service craftsman mowers for a living

FWIW even straight 30wt has detergents, the only time it doesn't is if it says "detergent free" or "non-detergent formula".

I did break down and get some straight 30w a couple years ago. I asked the guy behind the counter why non-detergent is recommended for small engines and he said it's because they don't have a filter. Don't know if he knew what he was talking about or not, but it doesn't really make much sense to me, if you think about it, you'd want the detergents to wash things down into the pan where they could be drained out periodically.

I've decided to try the MMO in both the oil and fuel to see what it does. In the recommended concentrations, there isn't enough there to do any harm, so what the heck. Not sure how long it will take to see results, some say it's immediate, some say it takes time.

Current plan is to change the oil and the MMO to both the oil and fuel. Run the equipment for an hour or so and check the condition of the oil. If it's all dark and sludgy looking, I'll change it again after 3 to 5 hours of use. I'm hoping that it will clear up a start/rough running issue my friends mower is having. It doesn't do it for me, of course, only her. I'm thinking she doesn't have the beans to start it.

Oh, and thanks to all who have offered your experiences. Much appreciated! I'll update when I have more info.

the only reason i know anything about non detergent oil is because of my involvment with air cooled vw's.
one of the questions we ask people who come in for service is how old the engine is if it's an original pre-74 we use non detergent oil, if we used detergent oil it would knock down alot of mung and really mess up the engine.

i use straight 30wt in my mowers, never paid any mind to what kind of oil it is, we're talking about briggs and stratton, you could use vegetable oil and it would be fine. lol

Yeah, at the moment I'm only interested in using it in small engines. I'm starting with the lawn mowers. If I like it there, it will be going into my rototiller, chipper, and pressure washer too. The chipper is 40 years old with a B&S engine, interestingly, it wasn't used too much and was garage stored. I did have to go through the carburetor though.

that makes a lot of sense that even straight 30w will have detergents today. Most of what I've dealt with is the guy with that 'old' bottle on the shelf that is non-detergent.

for rough start/running issue I'd suggest the plug, but it sounds like there are more experienced small engine guys here than myself. I can tell you that my left shoulder is still affected by attempting to start poorly starting small engines for years.