after i washed my 300ex tonight, i put gas in it than started it up. After about a minuet of running it, i looked down at my header and it was bright red hot. I shut it off emedietly. I dont think it is my oil because i just put new oil and oil filter in today.. What do you think it is????

 

check out the tech connection. some guy had this problem on his Polaris. I think they said something about the air and fuel mixture.

 

Check your valves they are going tight. I had this problem with my 250X. I had to adjust them at least once a year.