Feel the radiator hoses to see if they're all hot. Radiator could be dirty and need to be washed out especially around the back side. Plus you can do a radiator pressure test. Must hold 10psi. If it leaks down could be because of another blown gasket,a warped head or cylinder causing the problem.

 

How did this story end head gasket? I know old feed just curious

 

idk how it ends but my 1998 sportsman 500 4x4 will blow into the overflow when I rev high read up on several things about it and one I think is with my case waterpump bearing (if bad or going out can let crankcase pressure though and blows out at full throttle

 

So I just bought my first quad a 2000 Yamaha blaster. I know it's pretty small but I haven't ridden in like 10 years so I'm super excited. Anyone got any recommendations on things I can do to get more power out of my quad

 

New exhaust, new air filter, new tires, and you could big bore it but that will take a lot more work

 

The so called HO cam is the same as any other 509 cam. The only thing that made those year machine HO was a decal kit the manufacturer put on them to charge more money.
The only thing different is some models had a slightly larger carb in them. That Is It.