My odometer on my xr250 doesnt work. i am wondering if anyone knows of common things that can go wrong with it and how to fix it. i am not sure just what part is wrong on it but it doesnt keep track of the miles. Does anyone know how th fix them. Also there is an oil leak coming out of the counter sproket do i need to fix it or should i just leave it go. Is there a common seal that goes bad? any information will be apriciated. Thanx