oil leaking from filler cap
 

I changed my oil two days ago and noticed a fair amount of oil leaking from the filler cap after riding. The o ring is in great shape and seated, cap obviously tight. What I did notice when I changed the oil and filter was that it took about 4.7 quarts to get a proper reading in the sight glass, when the manual calls for 4.1 quarts. Would half a quart cause it to over flow from the cap?

Did it leak before the "laying on of hands" ?

it just means you didnt give the oil time to Settle,you have to take oil out and than set it at its mark.

It didn't leak before

What I did was drain, change filter, refill with 4 quarts, started and let warm up. level was right below lower mark, so I put in a little more, waiting 5 minutes, and checked again. I did that a few times until I got it right below the top line, but maybe I didn't give it enough time to settle.

4.1 is max for a change, I always tilt it onto the side stand to drain as much as possible so I figured I may have for a little extra out. Seems like I put too much in, its just weird it would leak from the cap.

So is this overpressurizing the crankcase from the increased oil volume? (downward motion of pistons increasing crankcase pressure)
I am thinking the filler is at the top of the case so there must be a significant atmospheric pressure increase to blow oil past the o-ring. (since liquids don't compress)

I have weeping at the filler cap, also. after each session at the track, I had to wipe a tiny amount off the cover.

I'll buy a new filler cap & o-ring.
I heard someone suggest to wrap the threads with Teflon tape....?

Did you check the oil with the bike on the sidestand? Thats what it sounds like. You check it with the bike plumb (balanced up & down). There should no way be pressure on the filler plug, and oil doesnt need time to "settle" unless its -25F.

Nope, I know what I'm doing. I double checked the level again and its still between the lines, but I'm still getting a small drop after 30 minutes. O ring shows no cuts or flaws and is not dried out or loose.

Wouldn't excess oil be expelled via the crank case breathers?

I use a small bubble level on the gas tank cover to be sure it is level when I check
my oil level. It does take some time for it to settle(oil). I have about 67k on my bike
and I have never had it leak from the filler cap. Maybe a drop or so. 4.7qts. seems a
bit much. Though I am using the factory oil filter on mine. If you are using a larger
capacity oil fitler it could use more to fill.