SaCCaL72

My Feedback: (1)

I was curious as to what After-Run-Oil is made of. I heard it was a 50/50 mix of ATF and Air Tool Oil. Thanks...

bbbair

I'm sure that the actual formula is a closely guarded secret.

But; the common home made variety is 50% ATF and 50% WD40.

britbrat

That's your's Bruce -- mine is 100% ATF

The real answer is --- petroleum --- unless its corn oil, or canola, or castor, or saflower, or peanut, or --- any convenient fluid that is ph neutral, has at least some lubricity, will coat the innards with a water resistant film, resists turning into glue, & can burn off without harm.

PropSpinner

My Feedback: (15)

Will Marvel Mystery Oil do the job?

SaCCaL72

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Does it matter what type of ATF? I have Dexron-III Mercon, is this ok? I was going to mix it with Air Tool Oil, I couldn't find Marvel Mystery Oil Air Tool Oil so I bought some other brand. I think it should work just the same until I can find MMO.

carrellh

From what I've read, Dexron/Mercon is preferred over Type F. Don't worry about finding MMO brand air tool oil, any air tool oil fights moisture.

SaCCaL72

My Feedback: (1)

Thank you for your help, I am going to mix me up a batch today. It is much cheaper than actually going out and buying After-Run-Oil, that's for sure... Thanks again...

FLYBOY

My Feedback: (11)

Thats what I use to lube an engine, but many use marvel tool oil. They like it better. I have never had a problem and don't use any oil after running unless I am going to store it. The oil in the fuel is enough and the nitro burns off quickly. Unless you live in a humid climate, I wouldn't worry about after run oil. Use tool oil to store them and they will last longer

britbrat

In practice, I really don't think that it matters that much if you use fuel with castor oil as part of the lube package. Last year I "found" a very old K&B engine in my garage -- it had been there for >30 yrs & it had been put away wet. It was gummed solid with castor goo, so I soaked it in fresh fuel until it would turn over, then I lit the fire & it ran beautifully (even the glo plug worked). After its resurrectional run, I decided to take a peek inside. I had to drill out some of the head-bolt & back-plate screws because the bolt-heads were so corroded that there was no way a tool could turn them. There was lots of castor varnish inside, but no rust.

iaclmac

I found this on the Saito information page:

"Use Marvel Mystery Oil (the air tool version is better), or any other brand of air-tool oil such as Snap-On Air Tool Oil. Other popular after-run oils are a 50:50 mixture of transmission fluid and air-tool oil, just transmission fluid, Mobil-1 synthetic oil, or any light oil such as 5W30. WD-40 is not recommended.

PropSpinner

My Feedback: (15)

I tend to agree! Oil is like insurance but the most important thing is to get all the fuel you can out of the engine at the end of the flying session. Many of the makers of fuel say you don't need to use after run oil with their products and some of the engine companies add corrosion resistance to their engines.

I know that the alcohol in a gallon of unsealed fuel will absorb the water out of the air and ruin the fuel. The same thing happens in your engine if you don't burn off the alcohol at the end of the day. It's the water that spots and rusts the crank and bearings. The oil provides a barrier from the alcohol/water. I would think that any combo that you would come up with you would want it to, seal the critical parts, penetrate the nooks and crannies of the engine well and burn off with no residue the next time you go fly. Also, oils that won't dry out and turn to glue after several years of exposure to the air would be a must. MMO seems to do these things for me but I'm sure there are others that do as good or better a job.

If you are going to store an engine I pull off the back plate and dump about a spoon full of MMO in the bearing, close it back up and put it in a plastic bag. The bag is to keep the oil from getting everywhere and the saw dust from my builds out of the engine.

Anyway I'm probably off subject so I'll shut up.[]

Rodney

Another good substitute for after run oil is Rislone (in the yellow container). Any air tool oil works well also. Do not use WD40 for long term storage. If you use it for cleanup or anything, rinse it out well with a good oil. Never use it in an older engine unless you want to agravate the wear as, any rust already present will be turned into a nice abraisive compound to accelerate the wear of the engine the next time you use it. While Marvel Mystery Oil is better than nothing, not by much. The Marvel Mystery Air Tool oil is good. On a 4 stroke, running the engine dry at the end of the day does little or no good. You have to get the gunk out of the lower crankcase and the only way to flush that out is to put at least a teaspoon full of after run oil into the crankcase breather hole and then turn the engine over by hand a few times while it is in various positions to completely coat the bearings down there. Even in the two strokes, you need more than a few drops to do any good.