What spark plug should i use in my 01 rm 125?
I always used NGK plugs in my CR250. The best in my opinion. How often you change it depends on how much you ride. You'll hear it when one starts going bad on ya. Or it just won't start at all. Here is a link. Has a chart for available plugs for your bike in various heat ranges. (the # at the end..8 or 9).
http://www.ngksparkplugs.com/apps/motorcycles/make3.asp
