CARBURETION L. P. Fuel Governed Idle

TM 5-4240-501-14&P CARBURETION L. P. Fuel Governed Idle Turn idle speed adjusting screw to obtain 1600 R.P.M. while holding throttle lever against screw. Release throttle lever. Align holes in control bracket and inside lever with 1/8" diameter rod. Governor speed control lever of equipment should be in IDLE position. Adjust if necessary. Bend spring tang to obtain 1750 R.P.M. Remove 1/8" diameter rod, Fig. 109. Fig. 109 - Governed Idle Adjustment Needle Valve Mixture (High Speed) Move governor speed control lever to "FAST" position. Turn needle valve in until engine slows or misses (lean mixture), then turn it out past the smooth operating point until engine runs unevenly (rich mixture). Now turn needle valve to the midpoint between rich and leans so the engine runs smoothly, Fig. 108. Engine should accelerate smoothly. If engine does not accelerate properly, the carburetor should be re-adjusted usually to a slightly richer mixture. L. P. GAS FUEL SYSTEM The following information is provided to assist you in servicing LP gas fuel systems. This information applies only to Garretson Equipment Company systems installed by Briggs & Stratton. For parts information refer to MS- 3915. Parts for the Garretson system must be obtained from a Garretson parts distributor. For information about LP conversion kits, contact: Garretson Equipment Co., Inc. Box 111 Mount Pleasant, Iowa 52641 or Beam Products Manufacturing Co. 3040 Rosslyn Street Los Angeles, California 90065 For LP fuel systems not covered in this section contact the manufacturer of the fuel system. WARNING: LP gas fuel system should only be worked on in a very well ventilated area. Many state, county and city governments require that service be performed only outdoors. Before loosening any fuel line connections, have a fan blowing directly across the engine. Checking and Adjusting Fuel System Loosen fuel line at primary regulator. Openvalve on cylinder for an instant, to be sure there is pressure in fuel cylinder. Escaping gas can be heard. Shut off valve at cylinder, Fig. 110, page 32. Remove fuel line between primary and secondary regulator (fuel controller). Attach pressure gauge to outlet of primary regulator, leaving gauge connection loose enough to permit a slight leakage of gas. (This will permit adjustment of regulator under conditions of actual gas flow.) Remove cap or top of primary regulator, Fig. 110. Open fuel cylinder valve. Turn pressure regulating screw in primary regulator, until a pressure of 1-1/2 pounds is obtained at pressure gauge. Shut off fuel cylinder valve. Re-assemble cap. Remove pressure gauge. Loosen secondary regulator bracket from carburetor. Pull secondary regulator away from carburetor so that short rubber fuel line is disconnected. Assemble fuel line between primary regulator and secondary regulator (fuel controller). Secondary regulator must remain mounted so the diaphragm is in a vertical plane, Fig. 110. Open fuel cylinder valve. Apply soap suds to outlet at the center of secondary regulator to which rubber fuel line has been attached. If a bubble forms, it indicates that the valve is leaking or not locking off. If no bubble appears, press the primer button. A bubble should appear, 30