Cox TD .010 problems with running

I recently acquired a Cox TD .010. Though it appeared to be in good condition, I nonetheless stripped it down and thoroughly cleaned it. Glow head is OK and I have spares. Upon running it a few times, it seems to have two problems:

1) I stops abruptly, even though it still has fuel and no air bubbles appear in the gas line. After priming and without adding fuel to the tank, the engine will start again and run until out of gas. What would cause it to stop suddenly, no sputters or any thing -- just stops?

2) There is no range in tuning the needle valve. I can not get it to go from rich to lean -- it just runs (apparently well though and at high RPMs) and any adjustment of the needle makes the engine die. Do I need a new needle valve and body? Or is something else going on?

One final note: I can not get any 1/2A fuel (though I live in paradise, apparently paradise does not include 1/2A glow fuel!), so I am using the only fuel I can get, which is 14% nitro, 30% lube (50% castro and 50% other).

Any help on these problems would be greatly appreciated.

Thanks, Eric

Seems a little heavy on oil, even Fox Superfuel is only 28%. The .010 I am keeping runs fine although a little sloppy on 15% nitro, around 25% castor. Maybe the high oil content is keeping it too cool?

Too much oil, not enough nitro.

The TD .010 can be really finicky on less than 20% nitro, and 30% would be better. Plus, 30% oil is a bit on the high side.

For a better run try 20% oil, 25% or 30% nitro.

Hi all,

I too have a similar problem. I don't want to hi jack this thread, but there may be a connection. I have 2 cox 0.01's. First is a second edition (black tank etc) The second is a first series gold and red device. It has however a black (replacement) tank. The first one runs fine, the second one will fire on an exhaust prime and then stop. I checked all the obvious things (fuel pipe venturi etc etc)and no joy, still fires on the exhaust prime and then stops!
Okay I have one good one and one bad, so a little parts swopping should identify the culprit.......a couple of hours later, still no joy! the only thing that I didn't swop was the tank......no it can't be that........Yes it was!!!!!!!! Swop tanks and the first edition runs and the second edition will only fire on the exhaust prime.....
Right folks this is a load of rubbish.....it cannot be happening....but it is!!!? Please would one of you Cox experts put me out of my misery.... what is going on here?
Could just be that the red and gold TD 0.01 is sulking and wants a red tank......anyone got one? I know it sounds incredible, but it is happening and I am at a total loss to explain what is going on. Has anyone got an explanation?

Regards,

Andrew Tinsley

The ideal fuel for the Tee Dee .010 is 30% Nitro, 20% oil (all castor or 1/2 and 1/2 with synthetic.)

Did you check that there is no obstruction in the fuel nipple and vent tubes in the tank? If either is sealed, you get no fuel flow. I recall that there is a gasket in the tank, and it can swell up and obstruct the fuel nipple.

Keep us posted!

Could also be the head clearance, too much makes engines very sensitive to needle and prone to quitting suddenly. Try taking out a head shim or two. The lower the nitro content the higher the compression required to keep the fire lit.

don Burke
Menifee, CA
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways - body thoroughly used up, totally worn out and screaming, WOO HOO, What a Ride!

> Could just be that the red and gold TD 0.01 is sulking and
>wants a red tank......anyone got one? I know it sounds
>incredible, but it is happening and I am at a total loss to
>explain what is going on. Has anyone got an explanation?
>

Doesn't seem all that mysterious to me - something is preventing fuel flow from the tank or air flow into the tank. If it runs out a prime but quits lean, it's obvious that it isn't getting fuel.

Brett

Anyone have any thoughts on why there is no range in adjusting the needle and why I can not get it to be lean or rich (it runs at one RPM only over a 1/2 turn of the needle and abruptly stops if adjusted further).

Eric

probably excessive oil level keeping engine too cool, try with the fuel Larry recommends, mine works fine on 25% nitro fuel.

See what Bret said above. The .010 uses a very small orifice in the needle valve assy and it can clog very easily. I suspect that yours either has a tiny particle floating in the spraybar or partially blocking the valve. Or....the air inlet into the tank is blocked or partially blocked. Neither of these problems would show air bubbles in the fuel line but would certainly cause the problems you describe.
Yes, there is too much oil and not enough nitro in the fuel but this sounds like a more drastic problem than that. Take the needle out and flush everything real good. Ditto on the air inlet into the tank.

Randy C

I need to be a little clearer on what is happening since some of the replies are giving answers to the wrong problem. The engine will start OK and run for an extended period of time -- say 30 seconds or a minute or two -- and then stop abruptly. There are no visible air bubbles in the fuel line and the tank is NOT empty. If I prime the exhaust port, it will start again and run for an extended period minute or more, and run out of gas (when it runs out of gas it sputters for a few seconds, stops, and you can see the air bubbles in the fuel line). So I am NOT talking about the engine simply burning through its primer; it will burn through a good portion of the tank before stopping abruptly. Furthermore, this is on a test stand, so everything is static. My experience has always been that if an engine is running well, has run for about a minute or so, it will run until the fuel tank is empty.

I can see that the fuel is probably not the best (thanks everyone for the suggestions ), but will the fuel cause this kind of behavior? I'll be hard pressed to get any other fuel. By living on an Island in the middle of the Pacific, and with Haz Mat and 9/11 rules, it is very hard to get or make any fuel except that sold by the LHS.

Eric

>I need to be a little clearer on what is happening since some
>of the replies are giving answers to the wrong problem. The
>engine will start OK and run for an extended period of time --
>say 30 seconds or a minute or two -- and then stop abruptly.
>There are no visible air bubbles in the fuel line and the tank
>is NOT empty. If I prime the exhaust port, it will start again
>and run for an extended period minute or more, and run out of
>gas (when it runs out of gas it sputters for a few seconds,
>stops, and you can see the air bubbles in the fuel line). So I
>am NOT talking about the engine simply burning through its
>primer; it will burn through a good portion of the tank before
>stopping abruptly.

Right, that was someone else's problem.


>
>I can see that the fuel is probably not the best (thanks
>everyone for the suggestions ), but will the fuel cause
>this kind of behavior?

Absolutely.

Brett

>>I can see that the fuel is probably not the best (thanks
>>everyone for the suggestions ), but will the fuel
>cause
>>this kind of behavior?
>
> Absolutely.

The described behaviour almost exactly describes what I got when I attempted to run one of my Babe Bee .049s on 5% SIG fuel. It would start easily enough and appear to run well, but would frequently flame out for no apparent reason before finishing the tank.

But on home mixed 15% nitro / 20% castor my .049s sing a merry tune right to the end of the tank, then cut off clean. Even 10% seems to be enough for good flights, but 15% really seems to make them come on to the right tune.

I did, however, have one Babe Bee that would run ragged and was almost impossible to needle reliably no matter what I did. On disassembly I found that the reed had a slight tear in it (not relevant to the original TD .010 question but shows the sort of things that can go wrong with Coxes). The engine was one of my original pair of Babe Bees bought in 1981, and had a metal reed which appeared to have succumbed to fatigue.

cheers,

Eric,
I don't know if this will help you but the car & truck guys use high nitro fuel which most hobby shops carry because of the popularity of this phase of the hobby. 30% or 40% nitro fuel for this application is usually easier to find than fuel for small engines. The only problem with this fuel is the very low oil content, sometimes as low as 9%. If you can find this fuel and find out what the oil content is, just top it up to about 20% with castor. I make up my 1/2A fuel from this source.

Thanks everyone for the info -- I'll try to get some different fuel and see how that works. For those who are interested, I'll give an update later.

Eric