Motorcycle Repair: losing coolant, blown head gasket, losing coolant

Question
Just a shot in the dark,ive got a yfz450 yamaha and its losing all its coolant from a small pipe connected on the pump(under)This only happens when it gets hot,dosent have a thermostat apparentley.Any help would be muchly appreciated!Cheers!!

Answer
Wade, I imagine that that little overflow tube is connected to the coolant pump to release pressure when the pump seal fails. Most coolant systems require a thermostat to regulate the coolant flow through the engine. When you take it out, coolant flows too fast, doesn't pick up enough engine heat and the whole thing goes into meltdown!

Pressure check the cooling system, to ensure that you don't have a blown head gasket, install a thermostat, bleed all the air out of the coolant system when you refill it and go riding!

This all assumes that the engine is not damaged, the radiator is not plugged, the pump is pumping, etc.

Bill Silver