Quite right, no scientific findings involved in my decision.

 

It was mainly based on two isolated observations. 

 

1.  The dozen or so rotary engines I've torn down (from cars) have been hideously dirty inside and require days of laborious cleaning before overhaul.  Many of the rotor seals were stuck in their grooves.

 

2.  A couple of two stroke engines I had (weed wacker and a chain saw) had piston rings stuck and ran very badly, was almost ready to throw them out.  After running some MMO in the gas, they soon recovered and are still in use today.

 

Later I added a 3rd observation after tearing down the engine in my RV-4 after 856 hours of flight time (using MMO and 2 stroke (50-50 mix).  It was so clean inside that the seals fell out of the grooves with nothing but gravity and it would have only required about an hour to prep it for overhaul if one had been needed.  There was almost no measurable wear on anything but the apex seals (about 33% of allowable wear on them)  It might have been just as good if I had run straight 2 stroke oil but who knows.

 

These observations do not prove anything.    But I do like the smell too  :>)  WalMart sells MMO locally for quite a bit less than the auto parts places ($12 gal last time I bought some I think)

Tracy Crook  (does not own MMO stock but probably should)

 

On Dec 31, 2007 5:34 PM, David Leonard <wdleonard@gmail.com> wrote:

A while back Tracy mentioned that he new uses 50/50 2-stroke oil and MMO(Marvel Mystery Oil).  Originally I believe that he used to use straight MMO.  I can't recall ever hearing the specific reasoning behind using MMO, and why the switch to 50/50.  I assume Tracy's thinking is based on conjecture and that is why he has not really expressed strong opinions to the group.

I considered it a non-issue as I saw no particular advantage to MMO, but now I am starting to reconsider.  My standard grade 2-stroke oil is dark and stinks like ammonia.  MMO is clear and has a pleasant smell.  Cost around here is $10/gal for generic 2-stroke oil and $18/gal for MMO.  You can pay much more for some of the "racing" 2-stroke oils (like $10/qt) so I have never tried them.  The MMO seems like a better quality product but I have no idea if it is doing what it needs to be doing when used as a fuel additive in our situation.

So Tracy, assuming that your reasons for using MMO are not based on any solid scientific finding, I would still like to hear why you decided to use it.  Other input welcome as well.  Thanks.

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net