Glow Plugs.......What causes them to go bad ?

[jgeorgic]

Being new to nitro what causes a glow plug to go bad a how long do they usually last ? :dontknow

Thanks !

Jeff G.

[mjws]

Usually they go bad when you are too LEAN. A bit of crud that gets ingested somehow can take them out as well. The good news is they usually stay lit when they fail, you find them on the next start. I've had them last a whole season or longer.

Mike

[Whirlybird]

They will fool you sometimes. I had a situation with my Rappy 50 where the engine would quit in flight but the glow plug would start the engine on the next try. Took me three autos before someone told me to change the glow plug. That fixed the problem.

[flyinfool]

I have seen plugs go 3 flights in a row on a well tunned engine and I have seen plugs last for 10 cases of fuel.
If nothing else has changed but the engine has started to run poorly, first step is a new plug.
Lean and/or dirt will take out plugs real quick. I have seen many plugs go shortly after a hot start due to the clutch dust being sucked thru the engine.

[ShuNut]

Interesting.
Any tips to get them to last longer ?
Like can that "clutch dust" be stopped from being sucked into the engine ?

Thx

[flyinfool]

Just don't do hot starts and the clutch dust is not an issue.

The best thing for plug life is to always run just a hair on the rich side.