My 2001 yz426f has a problem with engine coolant leaking from the weep hole under the side housing that holds the water propeller. This seems to happen only when the bike is standing still, even when it’s only a few minutes. Once it is moving again it seems to slow down or sometimes stop. I have changed the O-ring for the propeller housing and flushed the coolant but it still happens. The bike runs great and has tons of power, it starts on the first couple of kicks but I cannot stop for any length of time without shutting it off or it starts blowing out coolant.Is it safe to ride it? How can I fix this problem??