I WENT TO CLEAN MY FILTER A COUPLE OF DAYS AGO AND FOUND THAT THERE WAS BLACK OIL ALL OVER MY FILTER(FILTER WAS YELLOW) AND NOW ITS STAINED. I TOOK THE METAL THING OUT OF THE MIDDLE AND IT WAS DRENCHED IN OIL. WHAT IS THE CAUSE OF THIS?

 

What bike do you have?? On the Rancher, Recon, and 250EX (but not the 400 or 300EX), Honda puts the crankcase vent so it presses against the outside of the filter to keep it from getting dirt in it. I really like this system (especially compared to Yamaha who doesn't do anything!). Anyway, maybe you sucked some oil up from your crankcase vent???

 

Have you had you atv upside down or on its side? If so , then the oil may have entered the airbox through the crankcase vent. No biggie. Just clean and ride!

 

check your oil level also if it is over filled it will spit out the crankcase breather also