05 HONDA 450R COOLANT KEEPS SPITING OUT OF RADIATOR CAP, INSTALLED NEW WATER PUMP AND RAD. CAP. ALSO INSTALLED NEW HEAD GASKET. HAS BIG BORE KIT DONE TO IT. NOT SURE WHY IT KEEPS DOING THIS EVERY TIME THE RADIATOR IS FULL.

PLEASE HELP!!! I WANT TO SELL THIS THING

THANKS ED

 

I haven't had any experience with the 450 but usually when you get back feed into the radiator it's because of a compression leak into the water jacket. I really don't know and somebody help but does the head have a water passage and if it does it could be a head gasket problem.