Topic: Has MMO been used w/ success by you in the fuel for top end carbon ?

[grcamna2]

I want to know if any of you folks have mixed Marvel Mystery Oil in your fuel for a period of time to help clear carbon off of the rings and valve seats(the firing zone)as it's been known to do for years ?
I'm not thinking of severe carbon build up but just the usual carbon that forms from too many short trips and much use of the choke for years which adds up to less compression..  I imagine it should help to soften that stuff a bit.
                         your thoughts

[Don R]

 I have used it in the oil on a sticky hydraulic  lifter and it did work. I removed the intake years later for a gasket problem except for the seeping water passage it looked good and I never had to replace lifters. I put some in a sohc4 once and it seemed to make the clutch grabby.
 I've used it in the gas but don't have any evidence it worked. I used seafoam once and the exhaust smelled like it was burning coal. I assume it was removing carbon.

[grcamna2]

I wouldn't use it in the oil on a wet clutch M/C engine,but I want to hear if it actually works as advertised when mixed into the fuel tank w/ a specific fuel to 'oil' ratio.
I'm looking to uncover the 'Mystery'  of MMO, lol

no Really  ,I just want to do some preventive maintenance toward my engines for the firing zone and decarbonize w/o having to take everything apart all the time;if I keep ahead of the carbon build-up w/ the MMO I might not have to take it apart much.

if it does clean the carbon off the rings,valves I could conceivably have better sealing and more compression. 

[calj737]

Do a Google search on "de-coking engine". You'll see most reference SeaFoam or other fuel additive. Hadn't heard MMO as a viable option...

[grcamna2]

gotcha Cal,yeah just wondering if any of you here have tried it mixed in the fuel in Any engine.

[ekpent]

I've read of guys 'back in the day' running a tad of that or a little bit of 2-stroke oil in the gas on air cooled engines in very hot hostile climates like the summer Southwest etc to help out the engine. Not sure if it helped or not on that front.

[Ravie]

Back when I was working on Corvairs...  we actually got the engine nice n hot and ran straight tap water very slowly into the intake. (too fast and you run the risk of hydro-locking it) I'm not sure what the idea was other than maybe steam pressure, but it did seem to help smooth things out a bit.

The best luck I've had has been SeaFoam very slowly poured directly down the carb while running, then a bit more, at which point I turned the engine off, let it sit, then restarted. If nothing else it sure created a crapton of smoke. That'd be a betch to do on an SOHC though.

[grcamna2]

I was even thinking of doing what they recommend to w/ it and pouring equal amounts straight  into a hot engine(I'm not too sure how much for each cylinder)into each spark plug hole while making sure the bike is on the centerstand and then replacing the plugs and leave it sit overnight or longer.They said it would loosen/soften the carbon on the rings and pistons so when you next started it up and start running it through the gears it would blow out lots of carbon and clean the firing zone up.I hope it gives me more compression w/ a better ring seal,haven't tried it yet.

[calj737]

Grcamna - SeaFoam makes a formulation for soaking, "Deep Creep" that is better used int he way you're describing. Normal fuel additive won't abolish built up carbon from an overnight sit. Deep Creep might. The best results I've seen is following any of the de-coking methods available on YouTube or searching thru Google. Even Honda had a de-coke process at the dealerships back in the day.

[grcamna2]

I've heard that about Seafoam 'Deep Creep' but haven't used it just yet.

Do any of you remember old mechanics 'back in the day' using MMO this way? I started this thread because over the years I remember a few mentioning it in this way and just thought some of you on here had heard of it also.

[Maurice]

Hop on the highway and open her up, win-win

[grcamna2]

Hop on the highway and open her up, win-win

When the weather warms up,I hope to have that stuff loosened/softened up so I can do just that   

Just want to say that it isn't a huge problem but just doing 'preventive maintenance';I want to have as much good seal on my rings as possible.
The stuff is bound to build up over time and I want to get rid of it regularly w/o having to take it apart.

[BobbyR]

Back when I was working on Corvairs...  we actually got the engine nice n hot and ran straight tap water very slowly into the intake. (too fast and you run the risk of hydro-locking it) I'm not sure what the idea was other than maybe steam pressure, but it did seem to help smooth things out a bit.

The best luck I've had has been SeaFoam very slowly poured directly down the carb while running, then a bit more, at which point I turned the engine off, let it sit, then restarted. If nothing else it sure created a crapton of smoke. That'd be a betch to do on an SOHC though.

The water cure has been around forever and it works.  I have seen it done on high end BMWs in the 70's when the emissions systems caused carbon knocking. The German wrenches preferred it.

To prevent hydro lock you use a spray bottle and spray water into the carb throat. The cylinder will stumble, when it gets back up to speed you squirt it again. In our case you have to do each cylinder individually. You can use the same port you use for carb synching to spray the water.

 What busts up the carbon is rapid steam generation. Water is cheaper than anything else.   

[333]

My Dad used to make this "cocktail" of MMO, denatured alcohol, and something else I can't remember, and pour it down the carb of our cars(difficult to do on a bike).  He'd pour it to the point of almost choking out the motor twice, and a third time killing it. The neighborhood would be filled with blue smoke. I don't remember him doing this with our Corvair van, but it's funny that Corvairs were mentioned here.

[grcamna2]

My Dad used to make this "cocktail" of MMO, denatured alcohol, and something else I can't remember, and pour it down the carb of our cars(difficult to do on a bike).  He'd pour it to the point of almost choking out the motor twice, and a third time killing it. The neighborhood would be filled with blue smoke. I don't remember him doing this with our Corvair van, but it's funny that Corvairs were mentioned here.

Did your dad ever take apart one of those engines? how much carbon did they have in them after 'the cocktail' ?