Model glow plug engines are extremely dependent upon the type and quality of the glow plug used. Enya glow plugs use a platinum alloy coil, which uses a thick diameter wire for long life. The thicker wire coil also eliminates the need for an "idle bar" as found on other brands of glow plugs; idle bars tend to reduce top speed slightly, to achieve a more stable idle speed. Enya's glow plug design insures both good top end speed and stable idle speed. Enya glow plugs also have a thicker battery contact at the tip of the plug for greater heat dissipation and better electrical contact. Altech Marketing presently stocks glow plug battery cords specifically for Enya glow plugs, which are standard equipment with Enya four-cycle engines. Other glow plug cords usable with Enya glow plugs are available from several other manufacturers. Glow Plugs Usage Tips Your glow plug temperature range is too cold when: The engine power is weak or has weakened from previous levels. The engine slows down considerably or stops after removing the glow plug battery, despite correct adjustment of the needle valve. For example, if a Number 4 plug gives you these problems in your engine, switch to a Number 3 plug instead. Your glow plug temperature range is too hot when: The engine suffers from pre ignition and loss of power. The overall engine running is rough The glow plug filament is broken or collapses frequently. These are several cures to these problems. We suggest using a fuel with less nitromethane content, using a larger size propeller or using an Enya plug number higher than the one currently in use. For example if a Number 3 plug gives you these problems in your engines, switch to a Number 4 plug. Stock Number Plug Number Plug Temperature Range Suggested Use JK100 3 Hot All Enya engines such as TV & four cycle engines JK110 4 Mildly hot All Enya engines, especially those used with 10%or greater nitromethane fuel JK120 5 Medium All Enya engines, especially the .40CX, .45CX and high nitromethane fuel/ JK130 6 Cold High compression engines and high niromethane fuel used in racing.