My bike seems to be taking an excesive amount of effort to start. When it is cold or hot not to bad, but when it has been ridden for awhile and then wait 15 minutes, and try to start again it does not want to start going to have a heart attack. My plug has a tiny gap on it, and it is kind of black. should I use emory board and sand it off? Maybe my magnito is kind of week, or coroded how do I clean it off or whatever. Just does not seem right. Too much effort to start. Have adjusted the carb pin thing up and down a notch still nothing.