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F-15 Fan 01-21-2008 02:55 PM

Simple Question
 
I am using automatic transmission fluid as an after run oil in my K&B .61 2-stroke. I want to know if I can start the engine with a little bit of the ATF in it. Does it affect how it runs and starts?

Charlie P. 01-21-2008 03:11 PM

RE: Simple Question
 

I want to know if I can start the engine with a little bit of the ATF in it.
Yes. Assuming you only put in a drop or two in through the carb and didn't fill the cylinder.


Does it affect how it runs and starts?
You won't notice it. May add two seconds of electric-starter time or you'll need to hand flip three or four extra times to wash it out with the fuel.

F-15 Fan 01-21-2008 03:13 PM

RE: Simple Question
 
I put a drop or two in the cylinder, should I remove that first?

Rodney 01-21-2008 03:40 PM

RE: Simple Question
 
A drop or two is not nearly enough ATF (or any after run oil) to do much good. You need to get enough into the engine to coat the front and rear bearing and connecting rod bearings in order to do any good. After all, the object is to displace any residual nitro and alcohol to protect the engine from rust or nitric acid (nitro and water form a dilute nitric acid--the water is attracted to the mix by the alcohol in the fuel) That means around a half teaspoon full or more and with you manually rotating the prop a few revolutions after you put in the oil to distribute to the points needed. It helps to rotate the engine while you are rotating the prop to get the oil to all parts. Yes, that means your first start after using ATF will take a bit more effort but the fuel will quickly remove the ATF (or any after run oil) when you go to start it up.

F-15 Fan 01-21-2008 03:43 PM

RE: Simple Question
 
Okay, thanks for the help.[8D]

Missileman 01-21-2008 04:29 PM

RE: Simple Question
 


ORIGINAL: Rodney

A drop or two is not nearly enough ATF (or any after run oil) to do much good. You need to get enough into the engine to coat the front and rear bearing and connecting rod bearings in order to do any good. After all, the object is to displace any residual nitro and alcohol to protect the engine from rust or nitric acid (nitro and water form a dilute nitric acid--the water is attracted to the mix by the alcohol in the fuel) That means around a half teaspoon full or more and with you manually rotating the prop a few revolutions after you put in the oil to distribute to the points needed. It helps to rotate the engine while you are rotating the prop to get the oil to all parts. Yes, that means your first start after using ATF will take a bit more effort but the fuel will quickly remove the ATF (or any after run oil) when you go to start it up.
The instructions on my bottle of after run oil says to install 3-4 drops, is Hobbico wrong with their recommendations?

Dr1Driver 01-21-2008 05:06 PM

RE: Simple Question
 
I've never seen the need for after-run oil and haven't used it in 25+ years. No engine problems. Of course, my engines are kept in a climate-controlled room.

Dr.1

F-15 Fan 01-21-2008 06:19 PM

RE: Simple Question
 
I had a problem, when running the engine with a drop in the cylinder and approx. 3-4 drops down the carb, it burned it, it ran eratically and lots of smoke and light discolorations on the cylinder head. Should I use something else?

carrellh 01-22-2008 01:34 PM

RE: Simple Question
 
Everyone who uses after run oil has their favorite. Here are a few I've seen recommended:

ATF: any brand but not 'Type F'
Full Synthetic Motor Oil: Mobil 1, Castrol Syntec, etc. The recommendations are usually a low viscosity like 0W-30 or 5W-30
Air Tool Oil: Marvel brand is popular but any brand is fine
Half ATF & half Marvel Mystery Oil (which is different than Marvel Air Tool Oil)

Montague 01-22-2008 01:40 PM

RE: Simple Question
 
I'm curious, why not Type-F ATF?

Personally, I use ATF (and I think it IS type F, though I'll have to check when I get home).

I don't use any oil after a normal day's flying. But if I'm going to store an engine or if it eats dirt or water or something (I fly combat, it happens a lot), then I really fill the engine full and put it in a plastic bag because it's going to leak oil everywhere).

Your brand of fuel also matters a lot, I rusted bearings in 2 engines before changing fuel brands, and no problems since then.


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