I took the carb completly apart a few days ago(99 WR400). I just noticed a tiny O Ring on the work bench. Didn't see it when disassembling the carb. It is not one of the accelerator pump O Rings (this one is even smaller then the smaller of those two) or the Air Cut Valve O Ring. The only thing I can see in the service manual is it looks like the pilot screw has a spring, possible washer, and an O Ring. I only have the spring. Any ideas other then I should not have taken it apart in the first place?