Had picked up a SuperTigre .61 ringed engine at x-mas time. Yesterday, it was a nice day and after flying my brushless Unicorn around, decided to break in this engine. Engine is mounted in a G-Stick, a stick like el-cheapo Ebay model you can grab for $30.
Basically, a beater plane that if ya crash, who the hell cares! Anyways, breaking in the engine, the instructions say turn high needle out 3 turns. After running full throttle for 5 minutes, I started to lean it out. Then engine quits. No big deal as the thing aint broke in yet anyways. This happened a couple of times. I was running Byron's 15% nitro, 20% lube. The last time I tried to fire it up, wouldn't start. Hmmm....fired right up before.....Oh...DUH!!! Tank just about empty. However, there was enough fuel in the carb in order to start. My Hotshot glow driver aint the greatest and matter of fact, its about dead. I try with another driver. Nuttin....Pull glow plug.
Connect to the glow driver that on my power panel. The wire of the plug does nothing. Weird. The driver works okay with a couple of old glow plugs I have. Anyone ever hear of a glow plug that runs for 10 minutes and dies? Its the plug that comes with the engine.

Dave...

In 5 years of flying I have not had any glow plug go bad. But I guess it is possible that a new glow plug might have a manufacturing defect that causes it to fail after only 10 minutes. Replace it and see what happens.

Also, look closely at the failed plug. Does the coil look crushed? Sometimes metal fragments from manufacturing are left in a new engine. These can bounce around while the engine is running and mess up the plug (and the piston, sleeve, head, case, etc).

It happens,could be a defective plug or it could have overheated. I had one blow while i was starting a new engine for the first time-that was really annoying. [:@]

Just looked at it. Coil looks okay. Maybees the it did overheat. Don't even know what brand it is. Using an 11x6 prop for break in.
Engine seemed to lean out just a little. Did the pinch test (pinch fuel line) and engine almost died. Which tells me its a bit lean so I cranked the needle a few clicks towards rich. Seems that the magic area is about a few clicks towards lean from the original 3 full turns. I still need to run a couple more tanks through it before I attempt to demolish the SOB! LOL!!! Too wet today to be foolin around with glow stuff and its also windy. My brushless wing though flew great in the wind! Its a great windy flyer as the wing planform is thin. Oh, would an OS # 8 plug run okay with byron's 15% in this super tigre? I run # 8's in everything except my Saito 4 stroker and the Evo .46.

Dave...

I've had glow plugs last for 3 years, and then I've had others that go out in less than a minute. It happens sometimes that you get a funky plug, especially if you deal with the cheaper brands of glow plugs. For the most part the OS plugs are the ones that have lasted me the longest.

Ken

An os #8 should be just fine. [sm=thumbup.gif]

A couple of things here. First, it's wise to use an old plug for at least the first run because there can be tiny bits of swarf left in an engine from the machining. Aluminium is deadly to the platinum in the glow plug coil which could explain why your plug stopped working.

Second, from the sound of things you had the engine running close to being peaked out and this should never be done with a new ringed engine. Manufacturer's figures for the number of turns out on the needle are only a guide and they can vary considerably in practise. A ringed engine, especially on its first run, should be run as slobbering rich as you can get it. This means really really really rich . After that first run you can lean it out a little more but always have it making that 4 stroke sound, not the high pitched normal 2 stroke sound, for the next 30 minutes or more.

I have the glow plug that came in my nexstar still working but most others come out of the pacage not working. I take one out of the pacage and put it in the engine and it dont work I use O.S. plugs but I have one out of maybe 15-20 that actually worked out of the pakage Its weird
karter

Then you're getting too much heat to the plug, or something. That many glow plugs shouldn't go dead on anyone...1 out of 15 OS plugs are good? Give me a break Something else is going on here!

Are you testing these plugs before you install them?

Karter - I've got to agree with 2Slow. Something wrong here. Are you isung a power panel or a poratable glow driver? A portable (1 cell) unit CAN"T overdrive the plug and if it has a meter you will usually be able to spot a bad plug. I have NEVER had a bad out-of-the-package OS plug.
If using a power panel:
1. turn down the power.
2. attach a new plug.
3. While watching the plug closely, slowly turn up the power until you get the glow you want. Don't over do it.
4. Remember the setting and don't go over that reading for that series (#8, A3 or whatever) of plug.


UnLucky Armpit - sounds like you just ran too lean and burned out the plug.