thanks alot! i have spares- i bought a bunch of little things when i took my bike to korea just incase. it uses the nut/special washer combo. that would be great if it is an o-ring seal. i havent had a chance to get the sprocket off but threw a good amount of oil all over the rear of the bike. i noticed a small leak comming from the wires that go into the igition cover. so i am not 100% on the source yet. i have to get the sprocket/chain off and clean it up and then start it up to see. just got to find the time.