Ryobi 790R Fuel Line Size . On ryobi 790r fuel line diagram. Drain any excess fuel from the fuel tank prior to servicing the carburetor or the fuel lines. RYOBI 0.095 in. x 110 ft. HeavyDuty Spiral Gas Trimmer LineAC04148 from www.homedepot.com Did your ryobi model r line trimmers/weedwackers, gas break down? The old lines have completely fallen apart. Manufacturers part number (oem) used for.