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12. CARBURETOR/FUEL PUMP

12-0

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CARBURETOR/FUEL PUMP

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SERVICE INFORMATION........................................................ 12- 2

TROUBLESHOOTING.............................................................. 12- 2

THROTTLE VALVE DISASSEMBLY ....................................... 12- 3

THROTTLE VALVE INSTALLATION...................................... 12- 4

CARBURETOR REMOVAL....................................................... 12- 5

AUTO BYSTARTER................................................................. 12- 6

FLOAT CHAMBER................................................................... 12- 8

FLOAT LEVEL INSPECTION .................................................. 12-10

CARBURETOR INSTALLATION.............................................. 12-11

AIR SCREW ADJUSTMENT ..................................................... 12-11

REED VALVE.......................................................................... 12-12

FUEL PUMP REMOVAL .......................................................... 12-13

FUEL PUMP INSTALLATION……………………………………………. 12-15

Summary of content (16 pages)

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12. CARBURETOR/FUEL PUMP SERVICE INFORMATION GENERAL INSTRUCTIONS • When working with gasoline, keep away from sparks and flames.. • Note the locations of O-rings when disassembling and replace them with new ones during assembly. • All cables, fuel lines and wires must be routed and secured at correct locations. • Bleed air from the oil lines whenever they are disconnected. SPECIFICATIONS Venturi dia.
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12. CARBURETOR/FUEL PUMP THROTTLE VALVE DISASSEMBLY Remove the rear carrier. (2-3) Remove the met-in box. (2-4) Loosen the carburetor cap and remove the throttle valve. Carburetor Cap Throttle Valve Disconnect the throttle cable from the throttle valve. Rubber Seal Remove the throttle valve spring, carburetor cap and rubber seal.
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12. CARBURETOR/FUEL PUMP Remove the jet needle by removing the needle clip. Check the jet needle and throttle valve for wear or damage. Needle Clip Jet Needle Needle Retainer 2nd Notch (STD) Throttle Valve Rubber Seal Carburetor Cap THROTTLE VALVE INSTALLATION Install the jet needle on the throttle valve and secure with the needle clip. Throttle Valve Spring Throttle Valve Install the rubber seal on the throttle cable and then install the carburetor cap and throttle valve spring.
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12. CARBURETOR/FUEL PUMP Install the throttle valve by aligning the groove in the throttle valve with the throttle stop screw. Groove Throttle Stop Screw Carburetor Cap Tighten the carburetor cap. After installation, perform the following adjustments and inspections. • Throttle cable free play (3-12) • Idle speed adjustment (3-11) Install the met-in box. CARBURETOR REMOVAL Throttle Cable Auto Bystarter Remove the met-in box.
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12. CARBURETOR/FUEL PUMP Remove the carburetor. Nut Bolt AUTO BYSTARTER AUTO BYSTARTER INSPECTION Measure the resistance between the auto bystarter wire terminals. Resistance: 5Ω (10 minutes minimum after stopping the engine) If the resistance exceeds 5Ω, replace the auto bystarter with a new one. After the engine stops for 30 minutes, connect a hose to the fuel enriching circuit and blow the hose with mouth. If air cannot be blown into the hose (clogged), the auto bystarter is faulty.
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12. CARBURETOR/FUEL PUMP Connect the auto bystarter yellow wire to the battery positive (+) terminal and green/ black wire to the battery negative (-) terminal and wait 5 minutes. Connect a hose to the fuel enriching circuit and blow the hose with mouth. If air can be blown into the hose, the auto bystarter is faulty and replace it with a new one. Auto Bystarter AUTO BYSTARTER REMOVAL Remove the auto bystarter cover. Remove the two auto bystarter set plate screws to remove the auto bystarter.
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12. CARBURETOR/FUEL PUMP AUTO BYSTARTER INSTALLATION Install the auto bystarter into the carburetor body until it bottoms.. Install the set plate and then tighten the two screws. Screws Bolt Auto Bystarter Set Plate FLOAT CHAMBER Screws Bolt Remove the two float chamber screws and the float chamber. O-ring Remove the screw and O-ring. Remove the float pin, float and float valve.
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12. CARBURETOR/FUEL PUMP FLOAT/FLOAT VALVE INSPECTION Inspect the float for damage or fuel inside the float. Check the float valve seat for wear or damage. Float Valve Float Seat Main Jet JETS/SCREWS REMOVAL Before removing the throttle stop screw or air screw, record the number of rotations until it seats lightly. Then, remove them. ＊ Do not force the air screw against its seat to prevent damage. Remove the main jet and needle jet holder.
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12. CARBURETOR/FUEL PUMP FLOAT CHAMBER ASSEMBLY Install the main jet and needle jet holder. Install the air screw and throttle stop screw according to the rotations recorded. ＊ Main Jet Needle Jet holder If the air screw must be replaced, be sure to perform the air screw adjustment again. Throttle Stop Screw Air Screw Install the float valve, float and float pin. Tighten the float screw securely.
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. CARBURETOR/FUEL PUMP O-rings CARBURETOR INSTALLATION ＊ When installation, do not allow foreign particles to enter the carburetor. Check the carburetor insulator and O-ring for wear or damage. Install the carburetor and insulator onto the intake manifold and tighten the two lock nuts. Connect the fuel tube and auto bystarter wire connector. ＊ Route the auto bystarter wire correctly Insulator and properly. Install the carburetor cap.
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12. CARBURETOR/FUEL PUMP Bolts REED VALVE REMOVAL Remove the rear carrier. Remove the frame body cover. Remove the four intake manifold bolts and gasket. Remove the reed valve and gasket. Intake Manifold Reeds Reed Stopper INSPECTION Check the reed valve for damaged or weak reeds. Check the reed valve seat for cracks, damage or clearance between the seat and reed. Replace the valve if necessary. ＊ Do not disassemble or bend the reed stopper. To do so can cause loss of engine power and engine damage.
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12. CARBURETOR/FUEL PUMP Outlet Tube FUEL PUMP REMOVAL Remove the frame center cover. Disconnect the fuel pump inlet, outlet and vacuum tubes. Remove the two fuel pump attaching bolts and the fuel pump. Vacuum Tube Fuel Strainer Vacuum Tube Outlet FUEL PUMP DISASSEMBLY Remove the four fuel pump body screws. Inlet Disassemble the fuel pump.
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12. CARBURETOR/FUEL PUMP Diaphragm FUEL PUMP INSPECTION Inspect the fuel pump diaphragms A and B for damage. Inspect each gasket for damage. Gaskets Suction Valve Inspect the suction valve, outlet valve and relief valve in the fuel pump body for damage, cracks or foreign matters. Inlet FUEL PUMP ASSEMBLY Spring Dowel Pins Outlet Relief Valve Outlet Valve Diaphragm B Assemble the fuel pump in the reverse order of disassembly.
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12. CARBURETOR/FUEL PUMP FUEL PUMP INSTALLATION Outlet Tube Vacuum Tube Inlet Tube Install the fuel pump and secure it with the two bolts. Connect the fuel pump inlet, outlet and vacuum tubes. Install the seat, met-in box and frame center cover. Fuel Pump Fuel Strainer Outlet Tube Measure the fuel pump output. Start the engine and disconnect the fuel outlet tube and place a clean container under the tube to check the fuel output. Output: 40cc/1500rpm/10 seconds .