hello i have a 2001 400ex and it was running very hot in the woods one day and it just shut off and i found out the spark plug blew out of the head and i took it all apart getting ready for a rebuild (before i saw the spark plug dont ask me how i didnt see that first) (but im happy i did tear it down) and i saw that the entire inside of my head after the carb boot intake side of my motor was white except for the intake valves but the exhaust valves were white and so is the inside of my header pipe also so was my spark plug ( does that mean its running lean if so what exactly is lean too much fuel or not enough) and i think my oil wasnt circulating how do i find out if my oil pump is bad and i took out the oil drain bolt for the case and no oil came out but it did come out of the bottom hose going into the case. I put a new filter in it and it was filled with oil but its a car filter so it got blocked up i think but its a k&n 113 thats what was in my quad before but it says atv me new filter does not