AIRCRAFT CARBURETOR OVERHAUL INSTRUCTIONS

1 marvel -SCHEBLERAIRCRAFT CARBURETOROVERHAUL INSTRUCTIONSfor modelsMA-4-5, MA-4-5 AAMARVEL-SCHEBLER PRODUCTS DIVISIONBORG-WARNER CORPORATIONDECATUR, ILLINOISMARVEL-SCHEBLERAIRCRAFT CARBURETOROVERHAUL INSTRUCTIONSMODELMA-4-5 MA-4-5AA2-17. SPECIAL TOOLS. (See figure 2-17.)2-18. CARBURETOR ASSEMBLY COMPLETE.(See figure 2-18.)a. Remove the cotter pins (2) from all six of the specialbolts (4). Slide the special lockwashers (3) off the heads of thebolts (4).b. Remove the six special bolts (4) and regular lockwashers. (5).c. Grasp the complete body and bowl cover assembly (1) inone hand and the CARBURETOR body and bowl assembly (12) inthe other hand and carefully separate the two assemblies bypulling Move the throttle lever far enough to permit the pumpplunger assembly to clear the float and unhook the pumpplunger assembly from the pump idle lever.

2 Withdraw thepump plunger assembly from the complete body and bowlcover assembly (1).e. Press downward on the spring seat (8) and remove thespring seat locating pin (6) from the pump plunger rodassembly (7).f. Slide the pump plunger rod assembly (7) off the end ofthe pump plunger and stem subassembly (11) and remove thespring seat (8), spring (9), and second spring seat (8).NOTEDo not remove the pump leather expanding spring(10) unless replacement s required, as this would belikely to damage the pump COMPLETE BODY AND BOWL COVERASSEMBLY.

3 (See figure 2-19.)a. Remove the cotter pin (15) from the float shaft (16).Slide the float shaft (16) out of the float bracket (55) andremove the float and lever assembly (14). Lift out the floatvalve (18).b. Remove the throttle body to bowl gasket (1).c. Remove the cotter pin (5) from the head of the specialbolt (6), and slide the special lock washer (7) off the head ofthe bolt (6). Remove the special bolt (6) and slide the mixturemetering valve assembly (13).d. Lift out the mixture control valve lever lock wire (8) andremove the mixture metering valve head spring (9), mixturemetering valve head washer (10), and the mixture meteringvalve head gasket (11).

4 Slide the mixture metering valveassembly (13) out of the throttle body (80) and remove thesecond mixture metering valve head washer (10). It is notnecessary to remove the horseshoe washer (12) unlessreplacement is Using a small chisel or thin screwdriver blade, break thesolder between the two bolts (56) and the float valve seat (19).Unscrew and remove the float valve seat (19) and float valveseat gasket (17). Remove the two bolts (56) and float bracket(55).f. Cut and remove the lead seal (2) and locking wire (21)from the air metering pin jet plug (22).

5 Remove the airmetering pin jet plug (22) and air metering pin jet plug gasket(23). Using the air metering pin gage (4, figure 2-17), removethe air metering pin jet (24, figure 2-19). The air metering pingage is inserted I the same manner as in figure 2-25. Slide theair metering pin (26) out of the air metering pin jet (24) andremove the air metering pin return spring (25).g. Bend the tabs of the fuel inlet gasket (2) free of the fuelinlet connection (27) and unscrew and remove the fuel Bend the tabs of the fuel inlet strainer gasket (32) awayfrom the head of the fuel inlet strainer assembly (31), andremove the fuel inlet strainer assembly and If removal of the two pipe plugs (33) is required, cut thelocking wire and remove the two pipe plugs.

6 Removal of theseplugs is not necessary unless replacement is Slide the special lock washer (37) off the heads of thethree special bolts (36) and remove the two lower bolts are secured with locking wireand the upper bolt is secured in place with a Slide the idle adjusting needle assembly (34) out of thethrottle body (80) and remove the idle adjusting needleretainer gasket (38).l. Bend the tabs of the special washers (42) free of the twobolts (41) and remove the bolts (41), special washers (42),andregular lock washers (43). Lift off the bowl vent strainerscreen housing flange (44), bowl vent strainer screen housing(39), bowl vent housing gasket (45), and bowl vent strainerscreen (40).

7 M. Remove the cotter pin (47) from the inner end of thepump idle lever screw (52) and remove the pump idle leverwasher (49). wrench (9/16-inch)..2M-12 Socket extension ..3M-13 Socket extension handle ..4M-94 Air metering pin shaft bushing reamer6M-96 Throttle shaft busing valve bolt peening arbor ..8M-101 Primary venturi assembling venturi extractor ..10M-102 AMain venturi extractor valve seat shaft packing tool ..13M-105 AThrottle shaft packing tool arbor ..14M-106 Main venturi assembling tool ..15M-107 Throttle valve bolt peening tool ..16M-122 Throttle shaft bushing remover.

8 Figure 2-17. Special tools for overhauling MA-4-5 Series Carburetorsn. Remove the cotter pin (50) from the head of the pumpidle lever screw (52) and slide the special lock washer (51)off the head of the screw. Remove the pump idle lever screw(52) and pump idle lever gasket (53).o. Remove the cotter pin (48) and separate thepump idle lever and bushing assembly (46) from the link onthe pump lever subassembly (67).p. Using a small blade screwdriver, pry the end of thethrottle opening spring (54) out of the throttle shaft and leverassembly (65) and slide the spring off the 2-18.

9 CARBURETOR Assembly Complete Exploded Viewq. Loosen the bolt (57) and slide the throttle lever (59) offthe throttle shaft and lever assembly (65). Remove the bolt(60) and throttle adjusting bolt spring (61).r. File the ends of the bolts (64) and remove the two bolts(64) and slide the throttle valve (63) out of the throttle shaftand lever assembly (65).s. Loosen the set bolt (66) several turns to free the pumplever subassembly (67) on the throttle shaft and leverassembly (65). Withdraw the throttle shaft and leverassembly from the throttle body (80). Lift out the pump leverassembly (67).t. Slide a small screwdriver blade under one of the1.

10 Complete body and bowl coverassembly2. Cotter pin3. Special lock washer4. Special bolt5. Lock washer6. Spring seat locating pin7. Pump plunger rod assembly8. Spring seal9. Spring10. Pump lather expanding spring11. Pump plunger12. CARBURETOR body and bowlassemblyReferences for figure 2-191. Throttle body to bowl gasket2. Mixture control lever3. Mixture control lever4. Mixture control lever5. Cotter pin6. Special bolt7. Special lock washer8. Mixture control valve lever lockwire9. Mixture metering valve headspring10. Mixture metering valve headwasher11. Mixture metering valve headgasket12. Horseshoe washer13. Mixture metering valveassembly14.