Contents: Disassembly ↓ Assembly ↓
Disassembly
Unscrew the screws securing the carburetor cover and carefully detach it from the body so as not to damage the gasket, float, economizer tubes and the transition system of the second chamber.
They take apart the lid (figure 41) carburetor in the following order. Using a 03X24.5 mm mandrel, carefully push out axle 1 of float 3 from the posts and, without damaging the float tongues, disconnect it from the cover. Remove gasket 4, unscrew the seat of needle valve 2. Unscrew fuel supply pipe 11 and take out fuel filter 12.
Figure 41. Carburetor cover parts: 1 - float axis; 2 - needle valve; 3 - float; 4 - gasket; 5 - diaphragm of the starting device with a rod; 6 - spring; 7 - adjusting screw; 8 - Starter cover; 9 - idle fuel jet; 10 - electromagnetic shut-off valve; 11 - fuel supply pipe; 12 - fuel filter; 13 - fuel drain pipe; 14 - carburetor cover; 15 - air damper; 16 air damper shaft with lever; 17 - air damper control lever locking ball; 18 Air damper control lever; 19 - lever axis; 20 - air damper drive rod mounting bushing
Unscrew the housing of the idle fuel jet 9 with the electromagnetic shut-off valve 10 and take out the jet. Unscrew the axis 19, take out the ball 17 with the spring, remove the air damper control lever 18, disconnect the air damper lever spring. If necessary, unscrew the air damper fastening screws, take out the damper 15 and the axis 16.
Disassemble the diaphragm starting device by removing cover 8 together with adjusting screw 7. Remove spring 6 and diaphragm 5 with rod. Disassemble carburetor body (figure 42). To do this, remove cover 3 of the accelerating pump with lever 2 and diaphragm 1 with spring. Remove nozzles 10 and 11 of the accelerating pump and nozzles of the first and second chambers. Nozzles 10 of the accelerating pump are removed only by the nozzle body.
Figure 42. Carburetor body parts: 1 - accelerator pump diaphragm; 2 - accelerator pump drive lever; 3 - lid; 4 - accelerator pump drive cam; 5 - power mode economizer cover; 6 - economizer diaphragm; 7 - fuel jet economizer; 8 - economizer valve; 9 - accelerator pump check valve; 10 - spray and accelerator pump with fuel supply valve; 11 - Sprayers; 12 - main air jets with emulsion tubes; 13 - main fuel jets; 14 - bracket for fastening the air damper drive rod casing; 15 - adjusting screw of the second chamber; 16 - adjusting screw stopper; 17 - Stopper cap; 18 - first chamber throttle valve opening adjusting screw; 19 - throttle control sector; 20 - first chamber throttle shaft with drive levers; 21 - second chamber locking lever; 22 - locking lever spring; 23 - second chamber throttle shaft with lever; 24 - first chamber throttle valve; 25 throttle valve of the second chamber; 26 plug; 27 - return spring of the second chamber throttle actuator lever; 28 - adjusting screw for idle mixture quality (composition); 29 - carburetor body; 30 - idle mixture quantity adjusting screw; 31 - Electric wire of the limit switch of the forced idle economizer; 32 - carburetor heating unit
Unscrew the nut of the first chamber throttle shaft, remove the cam 4 of the accelerator pump drive and the washer. Unscrew the fastening screw and remove the electric wire 31 with the limit switch of the forced idle economizer from the adjusting screw 30 of the idle mixture quantity. If necessary, unscrew the screw 30. Remove the plastic plug 26 with a corkscrew and unscrew the adjusting screw 28 of the quality (composition) of the idle mixture.
Remove cover 5 of the power mode economizer, diaphragm 6 and spring. Unscrew fuel jet 7 of the economizer. Unscrew main air jets 12 with emulsion tubes and main fuel jets 13 of the main metering systems.
If necessary, unscrew the throttle valve fastening screws 24 of the first chamber, remove the valve and take out the axle 20 assembled with the drive levers. Having removed the lock washer and unscrewed the throttle valve fastening screws 25 of the second chamber, remove the valve and take out the valve axle. Take out the bearings of the throttle valve axles of the first and second chambers.
Assembly
The carburetor is assembled in the reverse order. In doing so, pay attention to the following:
- the float should rotate freely on its axis without touching the walls of the chamber;
- the needle valve should slide freely in its seat, without distortion or jamming;
- in order not to mix up the jets during assembly, you need to pay attention to the markings on the jets and follow them when installing them table 2;
- after tightening the throttle valve mounting screws, the screws are caulked using a special device that prevents deformation of the valve axes;
- when assembling the accelerator pump, tighten the cover fastening screws 3, press the pump drive lever 2 until it stops, tighten the cover screws completely and release the lever 2.