I'm not sure if I have a bad glow plug or not... when I take it out and put the ignitor on it, the whole coil doesn't glow... Is it normal for the end of the coil not to glow? Also it starts out bright then will back down after a second or two, is it supposed to stay bright with the ignitor on it? Thanks for any help you can give me

Does the engine run reliably? That is the true test of a plug.

It should stay bright, but sometimes it looks like it's dimming a bit because your eyes adjust depending on how dark it is where you are at the time. Also, check your glow starter battery. A quick drop-off could mean that it needs a charge or a replacement.

I have seen lots of people blame their glow-plugs for bad engine performance, but usually they are just tuned wrong. I like it because I have a lot of 'bad' glow plugs to hand out at the field. I have not had a plug go bad yet, but I have only 9 gallons under my belt as a beginner.

Hope this helps,

Mark

On a good plug, all the coils will glow. But there are a thousand details that might have an effect. Is the plug choked with congealed fuel? are the coils mashed against the plug wall? is the element frosted looking? etc etc etc

The bottom line is that with a good plug in an engine, the engine will crank right up and won't drop rpm when the igniter is removed.

BTW, if you go out to Hobby Park or to RAMS or to WSRC in an hour or so, there will be guys there who'll be more than happy to talk your ear off about plugs. And if you're actually having a bad time starting an engine (just a guess) will help solve the real problem.

Your ignitor is the reason for what you're seeing. It's falling off under the load. When I light up a plug with the big lead battery in my flight box, the element stays bright as long as the plug is connected.

See...... there are a thousand details

I don't know if it's that or just bad luck with ignitors... the first one I got was a hot shot II.. it wouldn't charge anymore so I bought a Dubro with a beep tester. Well I'm not sure that I'm happy with it either because sometime if I move it around just right I can get it to beep and other times I can't on the plug, so that was one thing that was kinda leading me to think the plug wasn't so hot, because I've hardly used the ignitor at all. The thing is once I get the engine started it stays on and it's fine. So I'm wondering if the ignitor just isn't making good contact or something... any thoughts?

it's the last turn of the coil that's not igniting... is that a problem?

No,

That's where it contacts the threaded 'barrel' of the plug. It's not glowing because the barrel is absorbing some of the heat near the contact point. Try it in a darkened room. You will likely see that coil is glowing, but not as brightly.

What do you mean by, "It wouldn't charge anymore."? Do you mean that it would loose a charge rather quickly and need to be recharged? It might be because of a memory effect on the Ni-Cad battery in the glow ignitor. If you have a charger with discharging capabilites, hook it up to that and cycle it 3-5 times. Should bring it back to life

When I put the hot shot on the charger the light on the wall box doesn't come on... I just tried it, it had a little residual charge that went on quickly when applied to the glo-plug... then I plugged it in for a couple hours and it didn't do anything at all... I tried plugging it into the dubro charger but the light didn't come on for that one either, so I think somethings wrong with it