Spewing coolant out of the catch can

[pongerpetrolium]

I have a bit of a problem and I was hoping someone could help.

I have a '05 YFZ 450 with a Trinity 500 cc jug and piston, a set of hot cams, Trinity stage 4 exhaust, and a K&N intake.

Just recently the quad began to slowly lose coolant out of the catch tank at a rate of half the radiator every two or so hours. The machine doesn't appear to be over heating as I can hold either coolant hose in my hand. I have change the radiator cap thinging the spring was weak and not holding pressure but that did not help.
Is it a blown head gasket? There is no residual pressure in the radiator once the machine is cooled down and I cant find any sign of coolant in the crank case or exhaust.
Any help would be appreciated.

[pongerpetrolium]

A note also: The over heat light does come on as the level of coolant decreases. So I dont believe that it is an issue with overheating unless the water pump isnt working?

[saber6]

Sounds like a head gasket to me. Can you get a pressure tester on that cooling system?

[pongerpetrolium]

I spose that is the best way to establish whether or not the head gasket is the cause. Where would I be able to get a radiator cap to test the cooling system with or is there another place to pressure it up from?

[saber6]

I would see if tou can find one of these OTC OTC7991 Universal Cooling System Pressure Tester - SHOP.COM Does the spark plug have any strange color?