My 650 developed an overheating problem this spring and was blowing antifreeze out the overflow was told it was a head gasket issue and I had no reason to disagree because they were in horrible shape when I ripped it apart so I actually ended up building it into an 800 wild I was in the motor and just recently got my PCV and tuned it in and it’s still overheating exact same problem I’m getting air into my system somewhere if I have my rad cap open constant little air bubbles come up and I have bald it multiple times to make sure no air is in the system. Anyone know what else could cause this besides head gasket