i should have adressed this problem in jauary but never did and winter is coming and i need this solved. My sled ran good all season then one day it slowey started burning more fuel and the plugs started getting darker and darker. i switched plugs about 4 times in one day. by the end of the day i went from 10-12 mpg to 4-6mpg. my fuel pressure stayed the same so i know my pump isnt messing up. the carbs are spotless. the intake is a chamber airbox so no filters. the compression is the same as when i baught it, and reeds are tight.