TM 5-4240-501-14&PCARBURETIONTwo Piece Flo-JetPress new seat flush with body using screw and old seatas a driver. See Fig. 91. Use care to insure seat is notpressed below body surface or improper float to floatvalve contact will occur. Install float valve as shown inFig. 93.Fig. 93 - Float Valve VariationsChecking Float LevelWith body gasket in place on upper body and float valveand float installed, the float should be parallel to the bodymounting surface. If not, bend tang on float until they areparallel. DO NOT PRESS ON FLOAT TO ADJUST. Fig.94A and 94B.Fig. 94 - Checking Float LevelAssemble CarburetorAssemble venturi and venturi gasket to lower body. Besure holes in the venturi and venturi gasket are aligned.Most models do not have a removable venturi. Installchoke parts and welch plug if previously removed. Use asealer around the welch plug to prevent entry of dirt.Stake welch plug at least twice.Fasten upper and lower bodies together with themounting screws. Screw in nozzle with narrow bluntscrew driver #19061 or #19062, being careful that nozzletip enters the recess in the upper body. Fig. 95. Tightennozzle securely. Screw in needle valve and idle valveuntil they just seat. Back off high speed needle valve 1-1/2 turns. Do not tighten packing nut. Back off idleneedle valve 3/4 turn. These settings are approximatelycorrect. Final adjustment will be made when engine isrunning.NOTE: All carburetor adjustments must be made withthe air cleaner installed.Fig. 95 - Assemble CarburetorCarburetor AdjustmentStart engine and run to warm up. Then place governorspeed control lever in "FAST" position. Turn high speedneedle valve in until engine slows (clockwise - leanmixture). Then turn it out past smooth operating point(rich mixture). Now turn high speed needle valve tomidpoint between rich and lean. Next, adjust idle RPM.Rotate throttle counterclockwise and hold against stop.Adjust idle speed adjusting screw to obtain 1750 RPM,aluminum engines; 1200 RPM, cast iron engines.Holding throttle against idle stop, turn idle valve in (lean)and out (rich). Set at midpoint between rich and lean.Recheck idle RPM. Release throttle. If engine will notaccelerate properly, the carburetor should be re-adjusted, usually to a slightly richer mixture.Fig. 96 - Adjusting CarburetorGoverned IdleTo adjust for governed idle, refer to Section 4 for specificmodel of engine.Choke-A-MaticRemote Control AdjustmentOn Choke-A-Matic carburetors, the remote control mustbe correctly adjusted in order to obtain proper operationof the choke and stop switch. For adjustment, seeSection 4.26
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