I am having a very hard time starting my Ariens Professional with the AX291 engine. I siphoned most of the gas out of the tank. I can see some small black specks in the bottom of the tank floating with the remaining gas. What is a good way to drain the rest of the gas and clean out any sediment? I was then going to drop the carburetor bowl, but trying to get the gas out of the tank and the tank clean first.