just bought a 2005 yz 125 a few months ago, and rode it about 4 or 5 times with no problems. but the last time i went riding, the bike went through a gallon of fuel in about 10-15 min of riding. Bike ran fine, but went through fuel way too quickly. I just put more fuel in the bike and was able to trace the leak to a hose coming off the front of the engine (cylinder, cylinder head region.) So my question is: what is this hose and why is there fuel coming out of it?