1 - accelerating pump; 2 - auxiliary accelerator pump; 3 – vacuum chamber; 4 - starting device; 5 - vacuum branch pipe; 6 – a vacuum branch pipe of the distributor of ignition; 7 - accelerating pump; 8 - solenoid valve forced idling; 9 - chamber of the starting device; 10 - valve of the exhaust gas re-burning system; 11 - throttle position sensor.
Carburetor Components
1 - starting device; 2 - screw; 3 - hairpin; 4 - float; 5 - needle valve; 6 - needle valve seat; 7 - sealing ring; 8 - nest; 9 - holder; 10 - forced idle solenoid valve (SCSV); 11 - sealing ring; 12 - sealing ring; 13 - cover; 14 - spring; 15 - diaphragm; 16 - body; 17 - spring; 18 - diaphragm; 19 - bracket; 20 - cover; 21 - spring; 22 - diaphragm; 23 - body; 24 - main air jet; 25 - primary fuel jet idling; 26 - secondary fuel jet idling; 27 - cover of the float chamber; 28 - bracket; 29 - gasket for the cover of the float chamber; 30 - weight; 31 - ball; 32 - cork; 33 - sealing ring; 34 - ball; 35 - screw; 36 - gasket; 37 - primary main jet; 38 - secondary main jet; 39 - cover; 40 - spring; 41 - diaphragm; 42 - fuel mixture enrichment valve; 43 – fuel mixture enrichment tube; 44 - spring; 45 - ball; 46 - accelerator pump cover; 47 - diaphragm; 48 - spring; 49 - body; 50 - gasket; 51 - cover; 52 - spring; 53 - diaphragm; 54 - housing with mixing chambers; 55 - vacuum hose; 56 - vacuum chamber; 58 - lever; 59 - adjusting screw; 60 - throttle lever; 61 - valve lifter; 62 - screw for adjusting the frequency of accelerated idling; 63 - free lever; 64 - base plate; 65 - idle speed adjustment screw (SAS–2); 66 - spring; 67 - secondary lever; 68 - idle speed adjustment screw (SAS–1); 69 - cork; 70 - screw for adjusting the quality of the fuel mixture (MAS); 71 - carburetor body; 72 - idle speed adjustment screw (SAS–3).
Withdrawal
1. Disconnect the wire from the negative battery terminal.
2. Drain the coolant to a level below the intake manifold.
3. Remove the carburetor cover.
4. Disconnect the accelerator cable from the throttle lever.
5. Disconnect the vacuum hoses from the carburetor.
6. Disconnect the connector from the positive idle solenoid valve.
7. Place a container under the fuel hose connections to collect the leaked fuel and disconnect the fuel supply hoses from the carburetor fittings.
8. Turn out bolts and remove the carburetor from the engine.
Disassembly
Warning! Do not remove the choke and throttle valves.
1. On an automatic choke carburetor, remove the coolant hose from the carburetor body fitting.
2. Remove the trigger link from the free lever.
3. Remove the connector bracket.
4. Remove the starter.
5. Remove the accelerator pump rod from the throttle lever.
6. Remove the float chamber cover, remove the screw "B" and remove the carburetor body.
7. Remove the screws "A" and remove the float chamber cover from the main body.
8. To remove the float chamber cover, insert the blade of a flathead screwdriver between the cover and the main body, and using the screwdriver as a lever, slowly pry the cover off.
Warning! Do not use excessive force when removing the cover.
9. Remove the stud and then remove the float and needle valve.
Warning! Don't drop the float.
Warning! Be careful not to damage the needle valve.
10. Use a flathead screwdriver to pry out the needle valve seat.
Warning! When removing the needle valve seat, be careful not to damage the float chamber.
11. Remove the holder and the forced idle solenoid valve.
12. Use a thin-bladed screwdriver to pry out the tabs and remove the two pins from the positive idle solenoid valve connector.
13. Remove the accelerator cable support bracket.
14. Remove the idle jets and main air jet.
Warning! Use a thin bladed screwdriver to remove the jets and be careful not to damage the jets.
15. Remove the accelerator pump and check the ball and weight.
Warning! To remove the accelerator pump, do not turn the body with the mixing chambers upside down. Check the ball and weight through the holes in the gasket.
16. Separate the float chamber from the carburetor body.
17. Remove the main jets.
Warning! Use a thin bladed screwdriver to remove the jets and be careful not to damage the jets.
18. Remove the three screws securing the enrichment valve cover to the float chamber housing. Remove cover, spring and diaphragm.
19. Use a screwdriver to loosen the enrichment tube and remove the spring and ball.
Warning! The enrichment valve is made up of many small parts. Don't lose them.
20. Remove the four screws securing the accelerator pump to the float chamber cover. Remove the pump cover, diaphragm, spring and gasket.
Warning! Before screwing in the accelerator pump fastening screws, apply a blocking compound to their threads to prevent them from unscrewing.
21. Remove the E-clamp and washers from the secondary throttle shaft and remove the diaphragm spring.
22. Remove the two screws securing the diaphragm bracket to the carburetor body and remove the throttle diaphragm.
23. Remove the auxiliary accelerator pump.
24. Drill a 2mm hole in the center hole for the fuel mixture adjusting screw (MAS), then ream the hole with a 3mm drill bit. Insert a punch into the drilled hole and knock out the plug.
Assembly
Assembly is carried out in the reverse order of disassembly, taking into account the following.
1. Clean all parts before assembly.
2. Check that the air and fuel channels are not clogged.
3. When replacing jets, the old and new jet must have the same dimensions, as the jets are selected at the factory according to their performance.
4. Do not reuse O-rings and gaskets.
Examination
Check the condition and replace or, if necessary, repair the following parts.
1. Check that the air and fuel jets are not clogged. If they are clogged, wash them in solvent and blow with compressed air. Do not use metal wire for cleaning.
2. Check the diaphragms for damage and cracks.
3. Make sure the needle valve moves easily. If the valve is difficult to move or is stuck, repair or replace it.
4. Check the fuel inlet filter located above the needle valve for blockage.
5. Check float travel.
6. Check the operation of the throttle, choke and linkages. If they move with difficulty, wash them and lubricate their axles with clean engine oil.
7. Check the float chamber cover and carburetor body for damage or cracks.
Checking the forced idle solenoid valve (SCSV)
1. With additional wires, apply battery voltage to the positive idle solenoid valve connector pins.
2. Make sure the valve works with a clear click.
3. Check with an ohmmeter that there is no continuity between the connector pins and the positive idle solenoid valve housing.
4. Using an ohmmeter, measure the resistance between the positive idle solenoid valve connector pins.
Resistance: 48-60 kOhm at 20°C
Checking the throttle opening gap of the primary chamber
1. Using a drill shank, measure the gap between the throttle valve of the primary chamber and the housing.
Gap: 0.93mm
2. If the gap is not as required, adjust it by turning the adjusting screw. Turn the screw clockwise to increase the gap, counterclockwise to decrease the gap.
Installation
1. Check the condition and, if necessary, clean the mating surfaces of the carburetor and intake manifold.
2. Install a new carburetor gasket to the intake manifold.
3. Carefully install the carburetor on the intake manifold.
4. Gradually, in turn, screw in the carburetor mounting bolts so that the gasket is compressed evenly. The bolts must be tightened very securely to prevent air leaks between the carburetor and the intake manifold.
5. Connect the accelerator cable, vacuum hoses and fuel supply hoses.
6. Check that the vacuum hoses are securely connected.
7. Check that the air damper opens and closes fully.
8. Check that the throttle valve opens fully when the accelerator pedal is depressed.
9. Install the air filter.
10. Connect the wire to the negative battery terminal.
Warning! Before the first start, do not fill the carburetor air inlet with fuel to speed up the engine start after servicing the fuel system. To pump fuel, turn the crankshaft of the engine with a starter.
11. Check idle speed and adjust if necessary.