Hello all,
Today I went to a flea market/pawn shop type business and they happen to have an RC plane with a OS Max 15 FP on it. I bought the airplane for $20 and now I want to get the engine running.

I have a two part question. . . .

First, does this engine need a total break down and cleaning? It's got what appears to be dried fuel residue and the like on the outside of the engine, but when I took the back cover off of the engine to expose the crankshaft and piston assembly, it is very clean in there. No gummed up fuel or anything.
I have no problem taking the whole engine apart and making it squeaky clean, but is that neccesary? If there are just one or two things that normally need to be cleaned on these engines before starting and the rest of the engine normally is fine, then I'd rather clean just the one or two things. If this is the case, what are the parts that I need to look at? The needle valve assembly? The carbeurator?

Also, I have some nitro fuel at my house that is 10% nitro and 18% oil. I'm not for sure if the oil is synthetic or castor oil. All the container says (that I could find) was "Lubrication Package by Klotz". The brand of fuel I have is "Patriot RC". I did some research on the engine and read in the manual to have 20% oil in the fuel mix. My question is, can I use the fuel I have on hand? I don't want to destroy the engine by using the wrong fuel, but if it will work just fine without tearing it up then I will use it. I'd rather not go out and buy another gallon of fuel.


Thanks,
Nicholas

Pictures. . .

Originally Posted by PyroMan

First, does this engine need a total break down and cleaning? It's got what appears to be dried fuel residue and the like on the outside of the engine, but when I took the back cover off of the engine to expose the crankshaft and piston assembly, it is very clean in there. ..............

Also, I have some nitro fuel at my house that is 10% nitro and 18% oil. I'm not for sure if the oil is synthetic or castor oil. All the container says (that I could find) was "Lubrication Package by Klotz".

Nicholas --

It sounds like you got a good deal. The OS Max is a nice engine; getting a plane with it is just icing on the cake.

From the photos, the engine looks to be very clean. I would not be inclined to disassemble any further at this time. Use a Q-tip to clean any dust or dirt from the carb intake. Plug the carb intake with a piece of paper towel and block the fuel nipple, then give the engine a good brushing with a toothbrush. A little denatured alcohol will help cut the dried oil --- you could use fuel, but it will leave an oily residue that will just attract more dust. Add a drop or two of light oil to the intake and down the glowplug hole, then flip smartly to distribute the oil throughout the engine.

Patriot RC fuel is blended, I believe, by Wildcat Fuels out of Nicholasville, KY. If so, the Klotz package is an 80/20 synthetic/castor mix. 18% oil is a sufficient amount, but you can always raise it slightly by adding castor --- Klotz Benol is the castor component in Wildcat fuel and would by my choice for a castor source.

Before fueling up, be sure to shake the container well to remix any oil that may have settled out.

Okay, will do. Thanks for the info.

Well she cleans up nicely. . .

I did what you said. I used a toothbrush and some alcohol (I used isopropyl). I'm really happy with the way it came out. I hope to start it before the end of Thanksgiving break.

It looked very dry on inside to me, but it might be ok. There is usually no need to clean the engine on the inside, if it has been run on synthetic oils there will not even be any carbon on the top of the piston. The only thing I have seen that can be a problem, is that with castor oil the conrod can get frozen on the wrist pin. Running the engine in that state can make the wristpin rotate in the piston instead and wear out the holes in the piston. With the backplate off it is easy to check that the conrod slide easily over the wrist pin. It is then fine to just run the engine.