I have a '99 yz400f. I just recently replaced the top-end , and put 426 rads on it. Rads will not hold coolant. Filled them, jumped on as soon as I started it and took off after 30 seconds coolant was blowing out of the pressure relief hose when on the throttle. Also have a slow drip coming from a small hole in the right right side of the casing, it's a perfect circle and looks as if it's supposed to be there. Could it be a tadle-tale like what u see on a vehicle for a bad water pump seal? Bike is running a tad lean. Shouldn't effect the coolant that much, Right ?