I was just wondering how long should I go until I change the glow plug on my Evolution Engine? Is there anyway to predict or tell how often I should change them? Any help is appreciated.

I change mine when the engine starts to run poorly, or the engine dies when I take the glow plug heater off when starting. That said, I've had plugs last a whole season and only a few weeks... I think alot of it depends on the quality of the plug, how the engine is run (ie. too lean, too rich, or just right) which all will have a bearing on temperatures etc.