Marvel Mystery Oil...

sneaky_pete · Sep 7, 2004

MMO is what is used to be known as Upper Cylinder Lubricant, a fluid specified by motorcycle manufacturers from the days of flathead engines (and early ohv) when oil pumps were mostly metering devices to control oil flow to the bottom end and provided almost nothing to the top end. I still use it in older bikes for that purpose, but as far as I can tell it is mostly diesel. Can't imagine what purpose it would serve in a modern gasoline or diesel engine. As a matter of fact, most newer gas engines run so lean (for emissions control) that many fuel additives leave deposits on the spark plugs and are detrimental.

Pete

slowrev · Sep 7, 2004

From what I have seen over the years it seems to me that you can substitute ATF for Marvel oil and get pretty much the same results.

Just my opinion on this though.

Gatorboy · Sep 7, 2004

Here is just one of the many.... this one is 9 pages 

Hmmm, where are the other 8 pages?

Junkman · Sep 7, 2004

( Here is just one of the many.... this one is 9 pages 

Hmmm, where are the other 8 pages? )

Do you have to work at being obnoxious or does it come naturally????? /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif

Soundguy · Sep 7, 2004

I've used it to free up stuck rings in an engine that sat..

I think it's mostly stoddards solvent anyway..

Soundguy

Jim_in_Omaha · Sep 7, 2004

My dad and his buddies used to use it in the older BMW motorcycles. I've used it in my 2 valve BMW's over the years. The main reason I could find was it seems to help keep the top end clean. Some claimed it made the valve lash stay in tolerance alot longer. Could not prove it by me. I just ran the crude out of all the beemers I've owned. Add a little of the stuff. My valves have always been real close to spec after several thousand miles.

"My engines don't get cobs..."

thx
Jim

Dargo · Sep 10, 2004

A tablespoon of it in the morning keeps me regular. /forums/images/graemlins/grin.gif

B7500 · Sep 13, 2004

I had a snow blower once whose valve stuck. Besides removing the sparkplug and tapping the valve with a wooden stick the only thing that kept it from not sticking was MMO.
I'm sure the other posters are right and there is a whole new generation of lubricants that make this product "ancient".
Still, it worked great for me and I will continue to use it.
_Terry