loopsnut

Is there an optimum temperature glow plugs should run at? Do they get weak or cooler as they become more used? Is there any difference between the temp of 4 stroke plugs and 2 stroke? Thanks in advance.....loops.

Spaceclam

as glow plugs get older, their temp does not decrease or increase unless there is something such as oil caking to cool it off or insulate it which will also begin to inhibit combustion and you will notice it very easily. about the glow plug tempuratures, you want the one that works best with the engine and fuel you are using. higher nitro means it is more explosive and requires a cooler plug to prevent pre-ignition. if you go too hot on a hot plug, you will notice a serious loss of power, and an awful knocking sound. keep it up much longer and your engine is ruined. a plug that is too cool will also reduce power a little bit, but not by anything significant. however, your engine won't idle as well because your plug is becoming to cool to maintain the necesary heat to ignite the fuel properly. basically, tell me if you have a two stroke or a four stroke, and what percentage of nitro you are using and i will tell you your best bet. that doesn't guarantee anything, but i can give you a suggestion. the difference between a two stroke and a four stroke plug are as such. a two stroke fires every revolution so your glow plug doesn't have to be as hot. but on a four stroke, you are only firing once every other revolution on a slower speed anyway, so your plug has to be much hotter. needless to say, your sour stroke is designed to handle that hot of a plug so you don't get pre-ignition and will not run well at all on a two stroke plug.

loopsnut

Thanks spaceclam...I am running a YS 63 and 30% nitro, with a YS or OS type F plug. Got a new Flashpoint IR temp gauge and was curious if I could use it to monitor plug temps.

Thanks

Spaceclam

your plug should be fine. however, your temp guage will not measure plug temps. all it will do is measure engine heat. by itself, the plug will not get that hot. you choose the plug tempurature when you buy them. on 30% with a four stroke, an os #F plug should be fine. on a four stroke, you should never need to go cooler plug unless you are having pre-ignition problems.

DeepSpace

don't think nitro play's a factor in chosing the F plug for a 4 stroke.
I am flying a Saito 65 5% Nitro and the OS F plug is doing fine. My brother is Flying a Laser 150 with 1% Nitro (or 0%) and also an OS F and also runs very well. And you americans always use way too much nitro and they also run nice on the OS F.
Maybe if he doesn't you can try another Four Stroke plug brand. But don't put a 2 stroke plug into an 4 stroke engine, cause most of the times it won't work

Spaceclam

that's what i was saying. a four stroke plug will never be hot enough, because it looses so much heat do to firing every other up stroke.
a two stroke however, you could put a plug in that is much too hot. because of the price and weight of four strokes i usually assume that whoever has a two stroke, but that's why i asked

loopsnut

Thanks everyone....