All the auto cocks I have ever seen have a "screen" that is a tube about 3 inches long that sticks up into the fuel tank. It goes in from the bottom of the tank between the tank and the auto cock. It may be the only filter on your particular model. If so, I would go guy a generic inline fuel filter and install it between the auto cock and the carb. I picked up one at the lawn mower store for cheep! I also like to use the clear ones as well as clear fuel lines. That way you can see how the flow is going, or if there is any garbage, or air in the lines. I also get these at the lawn mower store, it's the only place I have found that has them. They are actually yellow colored lines.