I have an 01 YZ426F and every time I go to ride it I need to put coolant in it. Now it is coming out of the overflow hose by the cap. When I ride it, it is getting plenty of airflow through the radiator because I really don't ride it slow. Now when I come to a stop and turn it off it will start leaking water. Could this just be that I need to replace the cap or should I look at something else?