I have a question regarding that. I'll be running a Rossi 11.5 later this year. I was told to run an OS #4 in it. It's not much cooler then a #3 plug. This is a high compression engine and I too thought that these type of engines should run on cold plugs. So which is better, a cold or hot plug on high compression engines running 0-5% nitro?
East Coast Vario Field Rep
Size it up and then scale it down