if your talking about the one near the airbox, then this one can be taken off i did so on my 91 KDX200 when i took all the lights off, it's a voltage regulator for the lights, and yes voltage regulators get hot, but if it's burning to the touch hot then it might be bad, but if your lights are still working properly then i would not worry about it, the one that provides the juice for the spark is the round one mounted to the frame (ingnition coil), and then there's CDI but that isn't in a heat sink form, check your manual and you'll find this to be true