KEROSENE SYSTEM OPERAT1ON Power loss will vary between 15% to 25% and fuel consumption will be approximately 15% less while running on kerosene. Fig's. 294 through 299 illustrates various types of Briggs & Stratton combination fuel systems used. Due to the low volatility of kerosene, engines operated on kerosene-gasoline fuel systems can be started on kerosene, only when engine is at operating temperature. Cold engines must be started on gasoline and switched over to kerosene operation only after warmed up. After warm-up and while operating on kerosene, adjust carburetor needle valves to a point where engine runs smoothest, and accelerates without hesitation when throttle is quickly opened. When shutting down engine, the carburetor must be emptied of kerosene so the engine can be started on gasoline when cold. Refer to Flo-Jet carburetor for adjustment of carburetor and adjust carburetor while running on kerosene. To operate units equipped as shown in Fig's. 294 through 296, 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. 294, 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.  