Originally Posted by Jon Kerr
Quick nitro noob question. I run the #6 Ninja plug in my .21 buggy on 30% O'Donnell. It works great with no problems. But I hear about guys running a hotter or cooler plug for certain fuels and conditions. What plugs are hotter (higher number or lower number) and when would you change? What makes them different? Is it more or fewer coils? Like I said. The #6 is what I was told to run and it's been good. I just want to have a good understanding.
It is like changing the timing on a real car. The hotter the plug the sooner the fuel will ignite. Most engine companies give you a very hot plug to break in the engine but after that you will want to change to a colder plug.
Most of the colder plugs are made with a larger size of wire. Not that you can see a big differance but I notice that the colder plugs usually last a lot longer then the hotter plugs.