a rich bike will run cooler a methnaol engine wil lrun cooler outside temps will make it run cooler some steel like on stock is much thicker and the temperature coefficent is different ,obviously the exhaust gases will be much hotter than the actual pipe is .tons of variables ...insulated heat wraps will change the harmonic wave of a 2 stroke and can actually hinder the engine performance plus trap the heat in ,which is also bad