ORIGINAL: obiwan12
Hi all, I thought I'd chime in, in favor of the #8. I've used them in all my 2 stroke glow engines from a .25 to a 1.60 for the last 17 years. I've never had a single problem with that brand of plug. Most plugs will last 2 to 3 seasons, some a little more, some a little less. Usually from what the original poster stated, it sounds like you are running the engine too lean for maximum power. Back the engine off by 100 rpm to the rich side and you'll probably extend the life of your plugs.
On a side note, I've used fox and enya plugs along with the number 8 for the first five years of modeling with mixed results. I've usually noted during that time, that the non-OS plugs had a shorter lifespan.
TIFWIW.
My engines produce great power. I fly at sites that range from 600 ft ASL to 1200 ASL. Temps range from 20 degrees 20 % humidity to 95 degrees 90% humidity. As always, more power is ''observed'' in the cooler dense air of the winter/early spring than in the heat of summer.
Very true, the colder, drier, denser air will produce more power. These variable will have a much greater impact on engine performance than the glow plug, for the most part.
My experience is that the Fox in more than adequate for the sport flier. In fact it is often more advantageous as it is cheaper than most (here in the USA). I do tend to blow the insulators on some of my piped engine with the Fox and OS more so than other brands.
As I have said I use a full range of Rossi plugs while setting up and engine. Once I find the range that works best I search for a cheaper alternative. I will say it is almost never an OS glow plug. Fit and price has a large effluence on this decision.(Yes, I use an OS plug in my Wankels.)