Show adjusting tort plugs saves gasoline tractor engines should run at top efficiency with the gasoline situation becom ing increasingly serious due to demands for gas for combat uses farmers are being asked by the war wa food administration to cut their use of tractor fuel to a minimum while this request may seem extreme to farmers who have had their tractors stranded now and then by dried up fuel tanks W C krueger extension agricultural engineer at rutgers university points out that many tractors could be operated on 15 to 25 per cent less fuel through correct carburetor adjustment lubrication bri cation and proper setting of spark plugs and magneto ile he emphasizes that when it takes to gallons of fuel to plow a 10 40 acre field 40 to 80 gallons to disc that field 60 to 80 to haul a grain drill over it and 30 to 50 gallons to harrow it a 25 per cent reduction in fuel euel becomes important krueger offers the following su suggestions 9 gest ions for improving tractor efficiency 1 it is a common error to believe that the leaner the mixture the less the fuel used too lean a mixture wastes fuel causes overheating over heating invites valve trouble best fuel economy results from setting carburetor at a compromise between too lean a mixture for idling and a slightly rich mixture representing maximum power adjustment this setting can only be determined by trial under loa load d 2 magneto timing is often responsible for overheating over heating and uneconomical operation since the method hod of setting varies with the tractor follow the instruction book closely 3 set spark plug and magneto point gaps to recommended clearance occasionally put in new plugs when electrodes become worn 4 check valve tappets two or three times a season improper clearince clearance ruins more valves than all other causes put together 5 never shut off a tractor immediately after running at full load valve warping is often caused by not letting the engine idle a short time before stopping so that the valves may cool gradually 6 operate the tractor at full load as much of the time as possible it costs nearly as much to operate a tractor at half load as it does at full load maximum draw bar efficiency fici ency occurs when the load is heavy enough to cause wh wheel eel slippage in field operations approximately 10 per cent |