Hey all,

I have moisture in my OS 40 LA. I didn't realize it so I started her up at the field and she just sputtered and died. So, my instructor came over and said I had to get rid of the moisture but my question is how? I have condensation (i think) on the piston head of the engine. I store the plane inside and stuff so I'm not sure how it formed. How should I get rid of it? After run oil? Also, do I dump my tainted fuel at the dump? (I live on the Central Coast in California)

Thanks a bunch for the help ,
IBrakeForNobdy

I'm pretty sure that the moisture isn't in the engine itself. But more likely is it's in your fuel. I don't know of anyway to fix that other than tossing it out and open a fresh bottle of fuel. Maybe somebody else here on RCU knows of a way to get moisture out of the fuel.

Hope this helps.

I break,

The nitro in the fuel attracts moister like a magnet. If you have moister in your fuel there is nothing you can do about it but replace it. I do believe this is what your instructor means as any moister in the engine would burn out as good fuel burned through your motor when started. I have my fuel cap taped with fuel connections and fuel right out of my fuel bottle. I save the red inner cap to pug it after my flying session so that the nitro -methane doesn’t pull moister out of the air when sitting in my shop.

Here's my fuel can setup

You cannot get rid of the fuel at the dump. Since it is considered a hazardous material, you have to take it to a hazardous disposal facility. The best thing to do is call the local fire department headquarters and ask them where to take it, or find a hazardous waste disposal company.

Ibreak,

you have your lines taped into the red sealer cap that I mentioned. I know you can screw on the cover cap, but I found this not to be as air tight of a solution as I’d hoped and lost a half gallon of fuel to moister. I removed the child proof portion of the top cap and installed fuel hardware to it. I then use the red inner cap to further seal the bottle after my flying session.

So, you drilled your fueling hardware into the white cap then, after your done, you take out the fueling hardware and put in the red thing and put on the white cap over it like how the fuel comes?

Actually I drilled for the fuel hardware in the clear childproof part located inside the white cap. (mine was clear) I removed it with a small screw driver. the top part of the white cape doesn’t have the threads. When I’m finished flying, I just remove the fuel line that goes into the bottle, pop the red cap in to seal it and screw the clear cap on. My friend does almost the same, but he removes the clear cap with the fuel hardware and fuel lines altogether, places the red cap in and then uses a spare white cap on top. Ether way works great.

If the engine is shut off when it is not real hot it can get moisture in it. The fuel left in the engine will suck condensation out of the air. In humid climates or humid days it is good practice to run the engine out of fuel at a high throttle setting so any leftover fuel is vaporized. Your fuel may be ok. Put a little after run oil in the engine,pull out the glow plug and spin it a little bit then reinstall the glow plug and start it. Warm it up good and you should be able to tell if the fuel is ok. Keep your fuel out of the sun and in a stable temp cool dry dark place when in storage(not the garage).

cogburn is right, put your fuel in stable inviroment, my garage is heated.

I put my fuel in a shed where it goes to like 30 degrees (F) during the night and like 50-60 degrees (f) during the day if the doors aren't opened.

Stable cool temp is like 60-65' and doesn't vary at all. Yuo have the cool part but not the stable part. This causes the fuel jugs to breath if they aren't well sealed eventually causing contamination from humidity. Though unless you are in a real humid area it probably would take some time. Your fuel in the jug is probably ok. The engine in the plane though breathes easily and any leftover fuel in the engine will collect humidity out of the atmosphere quite quickly. Methanol is 'hygroscopic' meaning it attracts? moisture. []

BTW, Fuel is in the shed, airplanes are in the house...so does that mean my fuel is garbage?

Odds are that it is good. The only way to find out is to try it. If the engine runs ok burn it up. Otherwise get some new stuff. Fuel that is bad i burn in a coffee can out in the yard.