hey i need some help...i just purchased a 2000 400ex the guy i got it from said theres a slight trickle of a leak and a low tapping noise....he took it to a mechanic and he said tis the lower end bearings or somthing and would cost 400 dollars...it doesnt seem right....does anyone know what htat sounds to be the probelm...and what i need to fix it...thanks

carmen