My 03 YZ450 seems to be using an excess amount of fuel. When riding with my WR400 and CRF450 mates, they use 1/2 the amount of fuel I use. I checked the oil and it appears that I am getting some gas in my oil. I also notice that the vent tube from the top of the head is dripping a small gas. The valves were just adjusted. Anyone have any idea what could be my issue?