My bike overheats, when I'm doing a lot of real slow technical riding, such as uphill rocky climbs in 1 to 2nd gear. I've rejetted to a slightly richer mixture, and put Engine Ice in it. Ive also opened up the muffler, and regeared. Is there any thing substancial that could be done to make it run cooler. I was thinking of a KTM radiator fan.