Today I went to the park with my son to run the rc car around, we are using Byron race fuel, gen2, 16%nitromethanol, 12%lubrication on a #4 glow plug, i charged up my glow starter, but it kettle cooking out after about 5mins of minimum speed, should I try a hotter plug or colder plug? It takes a couple of pulls to start if its left for a minute or two.just think its the weather change over to winter.any ideas?