Overheating

[binegar]

I have an 05 450r the bike is getting hot and boiling Checked thermastat, I tried boiling the thermastat in a pan it would work but only if it was boiling hot should the thermostat open faster?sensor is good, hot start seems to be ok,fan is working also. i was told it could be the A/F mixture so took the spark plug out its black I Just had a piston put in 11/5 comprestion has hrc cam slip on hmf it has a 178 main in it now please help?

[Ichoptop]

thermostats are preset to open at a certain temp. I'm not sure what the stock honda temp is though. Most car thermostats open between 170 - 195. put a gauge in the water with it and see at what temp it's really opening

If it does open then it is functioning.

Might look at jetting or some other issue. Is the fan kicking on?

A black plug is a little rich....which usually doesnt caught an over heating issue.