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nitro engine very oily comeing from exhaust

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Old 05-06-2014, 04:48 AM
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seniorspud
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Default nitro engine very oily comeing from exhaust

Hi have a OS 61 FX there is heavy oily stuff coming from the exhaust can any one tell why this happening thanks. need help
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Old 05-06-2014, 06:30 AM
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LesUyeda
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What kind of oil are you running. Some types do NOT burn off. Castor oil, for instance, that is why one uses it.

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Old 05-06-2014, 06:55 AM
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Even with synthetic oil in the fuel, you will have a considerable amount come out of the exhaust system. That's normal. Depending upon the airflow around the model and the location of the exhaust outlet you may or may not get a lot of oil on the plane. The solution? Use lots of paper towels to wipe up after each flight, and a good cleaner with paper towels to clean up after the flying session.

You have nothing to worry about, what is happening is perfectly normal.
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Old 05-06-2014, 07:34 AM
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Rodney
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That is the oil doing what it is supposed to d0, carrying the heat from the combustion chamber. If there is no oil in the exhaust you are running your engine way to lean and it will be on it's way to never-never land.
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Old 05-06-2014, 09:46 AM
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If everything is right with the engine then it's just the nature of the beast. I usually mount the engine so I can deflect the exhaust away from the plane so most the time I have very little clean up. I was talked into building one plane as designed for that old school look with the engine mounted upright, it's my snot beast. Even exhaust deflectors don't help. That slime is just the oil doing what it is supposed to do. Mounting the engine at 90 degrees or more is a big help with the muffler deflected away for the wing and stab. It's something I give thought to during a build. Sometimes with ARFs your just stuck with it. Try an exhaust deflector, they often help.
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Old 05-06-2014, 11:07 AM
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the oil doing what it is supposed to d0, carrying the heat from the combustion chamber
I don't know where this every got started, but oil does very little of the cooling on a model engine. The specific heat of oil is quite low, and the volume is only about 1/6th of the fuel. Much of the "cooling" is the expansion of combustion gases which extracts the power from the fuel. Most is from the air passing over the head.
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Old 05-08-2014, 11:56 AM
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Two-strokes waste a lot of fuel out the exhaust. You may think it is just oil because the alcohol evaporates pretty quickly.
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Old 05-09-2014, 01:01 PM
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Now you know why the electric flyers call them 'slimers'!

Oil colour is important. If it's clear or very light brown all is good.

If it's dark grey or black with metallic flecks in it, it could be your
muffler is loose or something more sinister is going on with your
engine. - John.
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