Carburetor Repair Kit For Tillotson RK-31HS. Kit Parts Are Compatible With Up To 25% Ethanol In Fuel. Quality Aftermarket Carburetor Rebuild Kit Made to meet or exceed OEM specifications. Repair Kit For Tillotson RK-31HS Complete kit, includes welch plug, screen, needle & inlet lever. OK for use with fuel containing up to 25% Ethanol