87 quadracer 250, it's leaking out the overflow. Have tried different caps and still does it. Any ideas. Did a total rebuilt over winter and haven't rode it much since. All gaskets and seals. What could be the problem.. Thanks for any info

 

A head gasket leak will cause coolant to spit out of the overflow. Did you remember to recheck the head and base bolts a number of times during break-in?

 

Make sure you don't have any air pockets because when the coolant becomes hot the air will allow it to boil over and come out. If I remember right there should be a bleeder bolt at the top of the head.

 

I bleed the coolent, opened the bolt at the top of the head, and let some coolent run out, Didn't help at all. Do you think it's the head gasket???

 

Very well could be. If it was warped or you torqued it down wrong it could be allowing the compression from the cylinder into the water jackets which would pressurize the system causing the coolant to overflow. One way you could test this is to take a coolant pressure tester and an adaptor and place it on the radiator with NO pressure. Then run the vehicle and see if the needle shows increasing pressure. Here is a cheap fix, did you check to make sure the cap is ok?

 

I took the cap off my 1996 Cr250 and put it on, Still did the same thing
I have another question, when bleeding how do you know when all the air is gone? I might have did it wrong, Thanks