wear coolant problem

[Carlos RXT]

:ack: I yust bought a 06 RXT and had a problem with it that i yust dont understand the thing is that when i go full throttle for like a 2 minutes or so the machine starts to said its overheting and spills all the coolant out this ony happens when i go full throttle any ideas on what may be the problem. if i opened the head to see the head gasket, what things can i change on the motor when the head is out,to get better performance. if you could tell me how much would everything cost me.

Thanks
Carlos