I have a 2002 Honda rubicon 500 I just bought and when you try to put coolant into the radiator it goes straight into the motor and mixes with the oil anyone have any idea what it could be thanks

 

If you are lucky, a head gasket, but running right in could mean a cracked block. See if it holds compression thru the spark plug hole. Could be a freeze plug somewhere that popped out. I've owned a few Mazdas that would do that. They had a freeze plug in the cylinder head. If it is a freeze plug, don't reuse it, get a new one. On the Mazdas, I tapped for a NPT Pipe plug.