User manual HOLLEY CARBORETOR

[. . . ] Autolite Model 1940 Carburetor GENERAL DESCRIPTION ENERAL DESCRIPlJlON Refer to Figures 1 thro ug h 6 for views of the manual choke and automatic choke carburetors. The Model 1940 carburetor is a 1V (sing le-venturi) concent ric downdraft carburetor. The fuel leve l is contro lled by a dual-lu ng nitrophyl fl oat wh ich perm its high angularity operation to meet government and mil itary specifications . FUEL INLET SPARK VALVE PUMP ROCKER ARM PUMP LINK Fig. 3-Side View of Automatic Choke Carburetor IDLE LIMITER CA P Fig. [. . . ] If corroded or damaged by exhaust gases, it mu st be replaced. DIAPHRAGM SPRING ~ ~PH~GM . . 15-Removing Choke Diaphragm INDEX ~ COVER BI-METAL SPRING ~ COVER ~ GASKET ~ BI-META L ____ GASKET a~ Fig. Remo ve the th ree screws ret aining the diaphragm cover, ari d disconnect t he diaph ragm link (Fig. Remo ve t he diaphragm ass embly and diaphragm sp ring fro m the cover. Depress the diaphragm modulator spring and remove th e spring retai ner, spring and modulator sp ring sle eve (Fig . 16). SPRING RETAINER i • I ~ ~-CHOKE DIAPHRAGM THE BALANCE OF THE DISASSEMBLY IS TREATED THE SAME AS A MANUAL CHOKE CARBURETOR WHICH FOLLOWS. 8 MODULATOR SPRING SLEEVE Fig. 16-Disassembling Choke Diaph ragm Autolite Model 1940 Carburetor CARBURETOR DISASSEMBLY MANUAL CHOKE CARBURETOR 1. 19), choke wire bracket, and dash pot from the bracket (if one is used ). Remove th e pump rocker arm retaining nut , washer, spri ng and pump link. Separate the bowl cove r fr om the ca rburetor body by tapping w ith a pla stic hamm er or handle of a screwdriver. DO NOT scrap e either the bowl cover surfac e or carburetor body surface with a metal scraper such as a carbon scraper or screwdriv er. A scraper may be fashioned from a nylon or hard plastic material such as a delrin body mo ulding re mo ver. DISASSEMBLY OF THE BOWL COVER 1. Rotate the pump ope rat ing rod and disconnect the pump drive sp ring an d accelerat ing pump assembly. 18-Removing Pump Rocker Arm and Link Autolite Model 1940 Carburetor CARBURETOR DISASSEMBLY 4. 23). PUMP OPERATING ROD R ETA IN E R ~ \ SCR EW --. ::. . . . . . ~ Fig. 20-Removi ng Accelerating Pump Assembly JJrr '~:. n PUMP STEM AND CUP ASSEMBLY PUMP DRIVE II ~ _~ E : ~?, ~- SPRING Fig. Carefully remove the staking from the vacuum piston retainer with a bearing scraper or a sc raper made from an old triangle file (Fig . 21-Acc elerati ng Pump Assembly Detached PUMP OPERATING ROD Fig. 24-Removing Staking From Vacuum Piston Washer 10 Autolite Model 1940 Carburetor CARBURETOR DISASSEMBLY 6. It must be blow n out carefully from both the inside and out sid e of the cover (Fig. 36) . lf the parts are in stalled in a cleaning basket, the bowl cover must be placed on top so that it will not be damaged . Fig. 27-Spark Valve and Fuel Inlet Fitting and Valve Assembly Removed 2. [. . . ] The choke unloader is a mechan ical devi ce to partially open the cho ke valve at wide-open throttle. It is used to eliminate choke enrichm ent du ring cranking of an engine. Engines w hich have flooded or stal led by excessive choke enr ichment can be cleared by use of the unl oader. Insert the spe c ified drill between the upper edge of the choke val ve and inner wal l of t he air horn (Figs. [. . . ]