I have discovered an old 049 cox engine amongst my stuff and I am looking for a bit of info.
So far, I have managed to get it to fire, but not run if I take off the glow-head and put 3-4 drops of fuel directly into the engine. It is not running yet.
Does anyone have info on mixture settings, or a good starting point?
First, how long has the engine set amongst your 'stuff'? MOST likely you have a reed-valved engine that the reed is stuck... or fuel has gelled in the pick-up tube / needle valve..You may have to take it apart and clean it. Cox .049's LOVE nitro...20% or more and also use fuel with mostly (if not all) castor lube. also the glow head may be bad...
I am using 20%nitro 20%synthetic - I mixed up a small amount just to see if I could get this thing running.
I have not taken it apart yet, but it seems that when i pull the glo head off - checked it, and it seems fine - a nice glow when a battery is clipped on.
I have no more info about it, other than the fact it is still installed in an old Plastic CL plane. Hell, I even found the 2 original props, 5x2.5 and a 5x4 !
I will probably pull it all out and take a good look at it.
The nifty thing about this one, is that on the front of the engine, there is a geared cog, and a toothed ZIP starter! -This actually made it very easy to start the engine if I remember back those 20 something years.
If I can get it going, I was planning on using it on a 1.2-1.6M glider.
I only know of two - the TD range with front induction, and teh reed valve sort.
Stripping teh reed valve down by removing the intergral tank and cleaning it up in fresh fuel generally unsticks them and allows blocked needle cvalves to be cleaterd
Frommemory, if all reassembles correctly, 2 1/2 turns on the valve, prime till the plug hisses, flick and she goes. If not reprime - its impossible to choke the reed valve ones.
lean off once warm till it almost 2-strokes and chuck. Never had a TD.
1-1/2 to 2 turns out from closed should be a good staring point. You should be able to just squirt a few drops of fuel in the exaust port for a prime.
you didn't say what style it is. There were a couple of different types, the most common was the 'baby bee,' there was also the 'space hopper' and 'tee dee.'
I'm guessing that you have the baby bee. If so you may need to remove the tank and replace the fuel line and clean the reed valve. The fuel line they used would get rock hard after a few years.
They also need a high nitro fuel (~25%) to run well.
The fuel line is SUPPOSED to be stiff....this ain't no RC! Some even had a spring in the center of the fuel line to suck every last morsel of fuel. If it ain't cracked, don't take it off...just clean it with some fuel.
20% fuel will run her fine! Put a little castor in it to help remove the heat!
All cox engines with the ball and socket rod to piston connection should be run with 20% minimum castor fuel, period. That is unless you want to invest in the tool to swage the fit back to normal after a few flights. They run OK on 20% nitro but are much easier to handle on 30-35%.
What all this fuss is about is the fact that over the years, the pliability of the fuel line goes away and it will start leaking air where it attaches to the back plate.
It wasnn't intended to be. It had a different function from what we use in RC installations. Fact is, it was still pliable when new and would seal around the nipple. After a year or so, it list its pliability and would sometimes even fall off!
Ive seen splits too, caused by vibration and brittleness.
We used to just cut a new piece of fuel tubing, drill a hole in the side of the existing tank, and route the fuel tube from the needle valve nipple out to an external tank. 3 minutes of flight is not RC flying.
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