Yes, yes and not exactly. Generally speaking, liquid-cooled dirtbikes get hot in slow going because there's not enough air moving through the radiators. How fast you need to go to keep things cool depends on ambient temperature, among other things. But Team Green moto-guru Ryan Collins figures your cooling system needs to be burped. Why? "It was okay before you got it hot and pushed all of the coolant out, and hasn't lost any coolant since being refilled," he says. Then there's that bubbling noise. "The cooling system needs to be free of trapped air to generate the suction required to pull fluid from that overflow reservoir back to the radiators. There's a bleeder bolt on the left radiator. Remove or crack the bolt, then fill the radiator until coolant comes out. Tighten the bolt, fill the radiator the rest of the way and install the radiator cap. The KLX300R comes with a 1.1 radiator cap, but I'd recommend going to a 1.6 (part number 49085-1073) to help pressurize the system and lower coolant temperature. I'd also check the overflow reservoir and the hose that feeds it from the radiator. Make sure there's a good seal and no kinks. Fill the overflow reservoir with fluid. Start the bike and let it idle till it's good and hot, which will push the coolant and air into the reservoir. Shut it off, and as the system cools, it should draw coolant from the reservoir to refill the radiator."