Marvel Mystery Oil

[CraigH]

This was always a point of controversy on the Cessna site I was previously a member of: How many of you running small Continentals in your T'Craft use MMO as a fuel additive?

[David Price]

Curious what the results are when all, or near all have responded to the poll.
17 out of 155 as of this post. Need more people to respond!

[Steve]

I have been advised to try this oil on my "problem" engine. The compressions are low on each cylinder and I had alot of metal on the oil analysis (none actually seen on the screen). I am not sure but it might have sat for awhile before I bought it, the oil was at least 6 months old with around 18 hrs tach time, and it came from Louisiana (humid). I also had a mud dawber nest in the intake that almost left me stranded in a field, thus running very rich. Hopefully it is some rust that had built up and will look better in 10 hrs. when I check it again.

[Forrest Barber]

MMO

Steve run it about 5 HRS with MMO and then drain and even flush the sump a bit with K-1, or Stoddards solvent. clean screen put in fresh oil with MMO and run another five hours, check compression & screen, oil sample & see what you have. Did you pull rocker caps & look into the cylds through plug holes to see if there was visable rust?

[CraigH]

Looks like a pretty even distribution so far. . . . .

[Ron Greene]

MMO

Good article on Marvel Mystery Oil at the following address:

http://www.pipercubforum.com/marvel.htm

[CraigH]

Another plug for MMO: http://www.radialengines.com/faq.asp

[Hank Jarrett]

My vote (sometimes used) needs a little extra info. I have used it in my CAR, not my plane. I wouldn't have a problem using it as an assembly lube or on anything that needed a light oil but I have never put it in the fuel or sump on my plane. Don't know if I ever would, but it would take some convincing to get me to try it.
Hank (Maybe I'll get it here) J

[lktiller]

Yeah, We get stuff from this forum, sometimes more than we ask for! All in fun and for the greater good.
Love this place! (My medicine is wearing off)

Anyway, just my experience.
75hp cont. engine. On long x-c fill up with 100LL. Before using MMO the mag check would run rough on the lower set of plugs after one tankfull. I'd switch to that mag and run the engine lean, full power until it cleared. Or clean the plugs.
Now that I use MMO (less than the can says to use) that rough mag check doesn't occur. Same plugs and I don't touch them now between annuals.
With all that said, I'd rather use Auto Fuel. No lead, lowest octane. I'll still add just a bit of MMO when I think about it.

[CraigH]

Originally posted by lktiller
Anyway, just my experience.
75hp cont. engine. On long x-c fill up with 100LL. Before using MMO the mag check would run rough on the lower set of plugs after one tankfull. I'd switch to that mag and run the engine lean, full power until it cleared. Or clean the plugs.
Now that I use MMO (less than the can says to use) that rough mag check doesn't occur. Same plugs and I don't touch them now between annuals.

Same experience in over 350 hours with 90hp Cont. engines.