Alrite I have used to have a 00' yz426 motor in a 400ex frame and that thing after riding a while would always start dripping coolant out of the weep hole underneath the water pump cover, so I replaced the seals and everything and it continued to do it. Currently now I have a 01' yz426 motor in the 400ex frame and was out riding it tonite and I stopped and looked down and not just a little bit of coolant was leaking out..it was pouring. I could also hear like it was boiling. The radiator was very very hot so I am sure it was overheated, but I just wanted to know if that coolant shooting out of there so fast was just a result of the overheating? I am pretty sure the seals are good in this one..(it wouldnt hurt to check tho). Just let me know if this is normal...it does not do it when the engine is just running warm only when hot hot.