I have a 1979 yamaha enticer 340 deluxe, I was getting it ready this winter and it ran fine. A couple days ago i tried to fire it up and it died, now it wont start. Upon inspection, i saw there is no gas coming from the tank to the carb, just a little before the pump and after. It will start with gas down the cylinders, I also tried to prime it by blowing through the gas tank but all it does is push air through the lines its not pushing gas out, any ideas? Oh and i also found dark brown chunks on the bottom of the carb bowl if that helps any. Any ideas?