Help starting OS 40 - RC Groups
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Nov 13, 2012, 04:30 PM
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Help starting OS 40

I am trying to get an Os 40 running. Originally it started and sputtered for a few seconds but I could not get it running. Now after reading forums and trying to adjust I can't get it to even sputter.
It has the airbleed low end needle. Adjusted to halfway blocking the opening.
The high end has been adjusted to blowing into the tube until it free flows.
New glowplug and fuel is fresh.

I have tried different throttle settings and have had no luck. Which is why I am asking for help here now as I am a novice. I have read some posts about tuning. But I can't get it started to get that far.
The only clue I have to go on, is that while trying to start the engine. It is spitting out rusty colored fuel out of the exhaust. Do I need to soak the engine in the crockpot with anitifreeze? This seemed to work before , for me on another engine. Or are there better ways to tuning the airbleed low end settings?
thanks as usual for the help!!!!
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Nov 13, 2012, 04:50 PM
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Two stroke or four stroke 40?
Nov 13, 2012, 05:00 PM
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2 stroke
Nov 13, 2012, 05:10 PM
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Consider removing the glow plug, and giving a squirt of fuel into the engine. With the plug still out, and the engine inverted, spin the prop either by hand or with a starter. This should flush out any of the old oil and give you a good starting point. If you continue to see rusty oil, especially while running, you will need to replace the bearings soon.
Nov 13, 2012, 05:32 PM
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While you have the glow plug out, ... go ahead and connect the glow plug to your little charger you have for a quick visual check. The glow plug should glow bright orange if everything is working right. Don't leave it connected more that a few seconds. The sucker will get hotter than a firecracker. Don't ask me how I know this?

If you don't get the bright orange glow, ... then maybe the glow plug is bad or the charger needs to be recharged? I will check a few spare glow plugs and i have an extra charger too just to be sure if its the glow plug or the charger.

If your gow plug and the charger are working, ... then try the steps suggested by zx32tt, the cylinder with fuel. Turn the engine over a few times, and repeat this process two or three times until you're happy with the results. When you re-assemble the glow plug to the engine, ... make sure the engine is flushed out well. It should be fairly well flushed out first. If you dont flush out enough of the excess fuel, .. the engine may want to lock up during the starting routine. The reason is because liquids do not compress. Therefore if there is too much fuel in the cylinder the piston will try to compress it as it normally would but the liquid fuel is taking up too much space inside the combustion chamber.
Nov 13, 2012, 07:39 PM
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will try that... and see what happens thks
Nov 14, 2012, 12:41 PM
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Set the high speed needle at two full turns out. Crank the needle all the way in, and then two turns. That would be a rich setting but the engine should run. Good glow plug and good power source for the glow plug and it should run. From you description it sounds like it is a LA 40, it is a good engine. Not the most powerful one but certainly a reliable one.
Nov 14, 2012, 01:40 PM
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Found the source of the rusty fuel. The tank was covered in black gunk for lack of better words on the inside. I noticed my fuel container had a ton of dirt in the bottom. Pulled the plane apart and found the tank dirty. Was a plane I bought and it was tough to get too the tank. Once I install a new tank, I hope this will help with the problem.
Would running the fuel through some coffee filters be a decent idea to get rid of the junk in it?
Nov 14, 2012, 02:03 PM
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and if you can not remove all contaminants, then what? i would rather spend the money on new fuel than risk my plane. i am personally very fussy when it comes to fuel. water will pass thru a coffee filter and it does not burn worth a darn
those are my opinions, but do not quote me
Nov 14, 2012, 02:35 PM
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I agree, however due to budget constraints, multiple expensive hobby's and a wife that will not approve of anymore spending on them. I have to try and salvage what I can. (BOOOOOOOOOO) Guess I will see what the stuff looks like once I filter it.
Nov 14, 2012, 05:36 PM
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Lumpy05's Avatar
Use clean fresh fuel, put a filter in the fuel line. Save the questionable fuel for later after you have it running, if it doesn't work well you know it's gone bad but you will know that its not the engine. Are you flip starting or using an electric starter? An out of tune possibly crudded up engine may be hard to start at first. Borrow an electric starter once you have it running and tuned up it will be easier to flip start.
Nov 14, 2012, 06:04 PM
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electric starter.. Guessing I will be a few days away from trying it though. As I need to get fuel line an re-install a new tank.
Nov 15, 2012, 12:44 AM
jeffie8696's Avatar
Clean fresh fuel is always a good thing. If your fuel has rust I would suspect it is full of water, fuel absorbs water from the air if left unsealed.
Nov 15, 2012, 06:41 AM
the great Gassif´er

Don't try to salvage possibly bad fuel.... the savings is usually less than the damage.... And that is not only money-wise, but also in frustration.

Brgds, Bert
Nov 15, 2012, 10:16 AM
Registered User
The carb is likely plugged from the dirt. Maybe you can take a pipe cleaner like from the craft stores to clean the tubing in the tank and use a filter, and flush the tank a few times too. If the tank is really disgusting, well, never mind. As far as the wife not letting you spend money, just sneak around like the rest of us have to.

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