Fuel Pumps (Crankcase Vacuum Operated)

TM 5-4240-501-14&P Units equipped as per Fig. 114 and Fig. 115, close fuel filter valve and open bleed screw in needle valve to drain the carburetor. Close bleed screw. Remove wing plug to fill fuel line and carburetor with gasoline. Combination fuel tank units, Fig, 112 and Fig. 108, open gasoline shut-off valve "A," and close kerosene shut-off valve "B" two or three minutes before shutting off engine. This will stop the flow of kerosene to the carburetor, and will admit gasoline to the carburetor. Fig. 114 - Kerosene Fuel System Fig. 115 - Kerosene Fuel System Fuel Pumps (Crankcase Vacuum Operated) Some models are factory or field equipped with fuel pumps operated by crankcase vacuum. Fuel pumps may be mounted directly to the carburetor or on a mounting bracket, Fig. 116 or Fig. 117. Crankcase vacuum is obtained by a fitting on the dipstick tube, Fig. 118, a hollow bolt and fitting, Fig. 117, or from the crankcase breather valve, Fig. 116. CARBURETION Fuel Pumps Fig. 116 - Pump on Carburetor, Breather Valve Vacuum Fig. 117 - Pump on Bracket, Vacuum thru Hollow Bolt Fig. 118 - Vacuum from Dipstick Tube 33