I own a 1/8 scale nitro buggy with a .28 hs engine. Today i installed a brand new glow plug into it made by traxxas. (My buggy is not traxxas) it started i ran it for 30 seconds then pinched th fuel line to check low speed needle for to rich or too lean. It ran about 5 seconds so a bit rich. But it would not start back up. I remove glow plug and it will not glow. So i pulled a glow plug that is also from traxxas out of a .18 hs engine check it to make sure its not my igniter pack it glows just fine. Now this glow plug has about 2 minutes of run time in the other truck. So i install it in my buggy and run it again 30 seconds. Pinch fuel line and try to start it. Now this glow plug is dead as well. I kmow the buggy is a tad rich but it should not kill a plug in 30 seconds. What else may be causing this that im over looking. As im bout to sell both these nitro vehicles on ebay

Plug die for many reasons. You say you ran it for 30 seconds. Was that at idle or wide open throttle? If you ran full throttle for 30 and the plug is dead, that means the high end is really lean. try opening up the high speed needle a bit. If you have a bearing going out, the metal particle's will kill a plug fast.

Buzz.

A wet plug will not glow until it boils off the fuel. Are you sure the plugs are bad? Do you have a multi-meter to test them for continuity?

The car is runing rich on both high and low needles. I come to that conclusion as the "pinch" test takes longer than 4 seconds for the engine to die and when you give it throtle it has quite a bit of exhaust smoke and it tends to kinda bog down when you give throttle. As for the fuel being on the plug it was several hours later i checked it and still no glow. Fuel wouod have evaporated by then right?

Hi!
The pinch test is not the way to set the low speed needle! It's not accurat enough! You have to set both needles by ear! By listening to how the engine sounds and react, that's how racers do it and those that have been in this hobby long enough to gain experience running engines.
Sorry! But you probably just run the engine too lean blowing the glow plug , or your glow driver (1,2v Nicad?) was not fully charged.

Jan - with all due respect - I suggest you stick to airplane engines. It's clear based on past discussions about buggy engines (albeit posted erroneously in the aircraft forum) in the past that setting and running buggy engines is NOT as cut and dry as you make it out to be and your assumptions make you look foolish. Racers set their engines up very differently than bashers do. It would appear we are dealing with a bashed rig here, NOT a racer.

In the case of the OPs glow plug problem - I will bet you just got a bad plug or two. But showing a picture of the element/bottom of the plug will confirm it's demise. Please post a photo or two (well focused).

Thank you jan this is deffinately a basher rig as you said. But one thing i do think i should mention is that the original piston did break leaving some pretty small pieces of metal debris in the motor i assumed i got them all out when i replaced the piston and sleave. Also i am nearly sure the car is tuned more on the rich side than lean. And my opinion would be that it would tske more than 30 seconds to burn out a glow plug. Also my deductive resoning is that the plug itself probably isnt the culprit. I say that because the second glow plug was originally in another truck and didnt go bad until it was installed in the buggy. Anyway i will post a couple pics this wekend thanks to all of you who responded

Ok this is the original plug with only 30 seconds of run time

I can see fuel or oil pooled up inside the element. This will most certainly cause it to not glow unless your glow driver is fresh off the charger. Blow the oil out and put a well charged glow driver on it. If it doesn't glow, try another plug to ensure the driver is good.

Glow plugs rarely go bad that quickly. The element looks perfect and the base of the plug shows no color, so unless the glow plug was defective from the get-go, it should be okay once cleaned out.

It looks like it has melted too me. On the righthand side there are a few dropformations in the region when the plug would glow the brightest with power connected to it. My guess would be that the glow driver has killed the plug. What glow driver are you using?

Hi!
If you had a piston disintegrate in your engine previously it sure make sens why your glow plug broke.. Small aluminium particles react with the platium element in the glow plug and kills it instantly.

The glow driver is a type that you put one double a (AA) size battery into. The battery i used is a nimh 1.2 volt battery and was a little week at the time of the failure. But has since been charged fully. @jaka i am also leaning towards your diagnosis. So do you know the best way to clear any more remaining piston particles from the engine. I was thinking wd40?

Okey, then it is not the glow drivers fault, you would not be able to melt the element on a good plug by using a NiMh battery. Aluminium particles may well alloy with the Pt though and then it melts at a much lower temperature.

How did you get particles from the piston in there?
I guess the best is to take everything appart then and rinse in fuel. Particles may well be stuck in the ballbearings etc. so the crank needs to come out I guess. If you use a degreasing agent you'll need to lubricate immediately with oil. WD40 may work for rinsing, but you'll need to lubricate all the parts with an oil that is soluble in methanol afterwards.

Hi!
First of all you need a good reliable battery source. I personally don't like the small 1,2V NiCad "glow drivers" you put on top of the glow plug. They work fine for a person that has been around for some years but not for a "beginner". Why? Because the battery doesn't contain enough energy.
I myself is a "airplane guy" and has been for 42 years (boy what times flies...) and I I prefere using either a 12V 10A motorcycle battery and an automatic glow panel. A more modern way of powering the same is using a 14,8 Lipo 2A battery or a 13,2 V LiFe , 2,3A battery preferably coupled directly to my 12V Sullivan electric starter.

As for cleaning the engine it's simple! Just take it apart and clean it with whatever you have, Aceton works fine.

@Mr Cox. I had a piston break apart where the pin holds the head and arm together. After I pulled the old piston out attached the new piston to the arm and installed the new sleave I rolled the crank a couple times and it seized up. I took it apart and noticed a tiny piece of metal from the old piston. Had wedged in the grove where the crank turns. I removed it and reassembled motor I'm not sure if there is any metal pieces left but it makes sense there would be some left over

So one more question. I also noticed the new plugs thatbwent bad quickly are actually a bit longer than the original plugs i was using for both the .28 size motor and the .18 size motor. The longer plug ran in the .18 size motor and didnt go bad until placed in .28 size motor so maybe thw size caused it having the plug sit closer to combustion chamber?

Hi!
No!
That's not the problem! There are three sizes of plugs (four if you count the OS F four stroke plug).
Short ones (no modern engine to day use those) , Long ones ( Most modern plugs are long like Rossi, Nova Rossi etc) and then the Japanese type like OS and Enya (These are a little bit shorter than the long ones and a little bit longer than the short ones).
All these plugs can be used without problems in most modern glow engines. If I recall right the K&B 3,5cc engines used short plugs, but those engines are not made any more.