Hey guys, has anyone experienced oil leaking from the filler cap?

I went for an extended ride saturday and toward the end of the ride my buddy noticed that oil had been slowly leaking from my filler cap. The general area was wet but the worst thing was that the right side of my rear tire was wet with oil as well! It wasn't too slick though and felt tacky to the touch.

The cap was on tight but there's no doubt that's where the leak was coming from... it was the hottest day of the year so far and I'm wondering if there was just some pressure build-up in conjunction with the plastic cap warping from the heat that could have let some oil out? Curious to know if this is a common occurrence. [EDIT] Forgot to mention that during my last oil change I filled it a little high. Not super high but just about where the top tick is on the window. I also noticed that the oil fill hole has a recess in it where an O-ring might go. Not sure if I'm just missing mine but I stuck an O-ring in there for good measure. [/EDIT]

Oh btw, I lifted my tank for the first time and underneath I found one end of a hose with a spring clamp on it. I assume this should be connected to something? I left it as is and went for an hour long ride without issue.

 

it plugs into the back of your airbox, it'll be pretty obvious once you peek in there, as you can see your fuel line is the other hose in the pic, it sneaks in beside it on the big black airbox

 

+1 to that... you'll see the large fitting on the back of your airbox where that goes once you lift the tank again. As for oil coming out your filler cap, the cap does have an o-ring on it, so i would guess that's why oil was coming out.

 

Ah, thanks guys! I'll lift the tank and look again. And thanks for confirming there should be an O-ring under the cap!