I started my yard machine riding mower for the first time today. Gave it a shot of starting ether and it kicked right off. I ran it up to fast idle and around the yard to warm up. As I was driving I could feel the rpms dropping off and the motor starting to stumble. I headed back toward the garage but it just slowed to a stop and wont start again. It did have an almost full tank of gas in it but I dont remember if I put extender in it or not in the fall. Do you think its a fuel issue? Guess I will drain the gas and change the fuel filter and see what happens but if not do you think i need to rebuild the carb too. Thanks