If your engine idle becomes unstable after changing the nitro percentage of your fuel, try the Redline R3. The Japanese made R3 is especially designed for airplane and helicopter engines. It provides great performance in the entire operational range, from stable idling to smooth acceleration. The R3 is a medium length, idle bar-less glow plug featuring a platinum alloy filament. This glow plug has been widely accepted by serious aircraft and helicopter modelers. If you are accustomed to glow plugs such as the O.S.#8 and the Enya#3, you will like the Redline R3.