Disassemble cover 10 (pic. 39) carburetor, for which, with a mandrel ∅ 2.2 mm, 30-40 mm long, carefully push the axis 16 of the float out of the racks (push to the side of the rack with a cut). The float with the needle valve 15 is carefully removed. The gasket 11 is removed, the needle valve seat 14 is unscrewed, the gasket 18 is removed, the plug 13 is unscrewed and the fuel filter 12 is removed. Having unscrewed the fastening screws, remove the air damper 9 and axis 8. Unscrew the two screws securing the body 6 of the starting device and remove it.
Unscrew the three screws securing the cover 2 of the starting device and remove the cover with the adjusting screw 1 and the spring 3. Remove the diaphragm 4 with the stem 5.
After disassembly, all parts are washed in gasoline, blown with compressed air and their technical condition is checked. The sealing surfaces of the cover must not be damaged. The float must not be damaged or deformed. The mass of the float should be 11-13 g. The needle valve should move freely in the seat, not wear. All damaged parts are replaced with new ones.
The carburetor body is disassembled, for which the screw securing the three-arm lever 24 is unscrewed (pic. 40) air damper control, remove the lever and spring 23, disconnect the rod 25 from the lever. Unscrew the screws securing the cover 21 of the accelerator pump, remove the cover with the lever and the diaphragm 20 with the return spring 19. Unscrew the main air jets 10 and 12, turn the body over and, lightly tapping along it, shake out the emulsion tubes 11 and 13 from the wells. Unscrew the housings 6 and 18 of the jets and take them out together with the jets and unscrew the screw valve 9 and remove the atomizer 8 of the accelerator pump with gaskets, unscrew the adjusting screw 16.
Take out small diffusers 7 and 22. Unscrew the main fuel jets 14 and 15. Unscrew the screws securing the body 2 of the secondary chamber throttle actuator and remove it, and then cover 4, spring and diaphragm 3 with stem 1.
All parts and channels are washed with gasoline or acetone, blown with compressed air. If necessary, channels and emulsion wells are cleaned with special reamers. Damaged parts are replaced with new ones. Check the ease of movement of the moving parts of the accelerator pump (lever, roller, ball in screw valve, diaphragm parts). Jets and emulsion tubes are cleaned of resinous deposits, washed with acetone or gasoline. Check the throughput of the jets and compare them with the reference ones. It is not recommended to clean the jets with a metal tool or wire and wipe with a cloth or rag. In case of severe clogging, the jets are cleaned with a softwood needle dipped in acetone.
Dismantling case 8 (pic. 41) throttle valves. To do this, the restrictive bushings 13 are removed, the idle speed adjustment screw 14 is unscrewed, the sealing ring 15 is removed, the screws securing the bushing 17 of the screw 16 of the amount of the mixture are unscrewed and removed together with the screw. The mixing sleeve 18 is removed. The tab of the lock washer is bent and the nut securing the levers on the axis of the primary chamber damper is unscrewed. Remove the lock washer from the damper axis, levers 1, 2, 4 and with washers and bushing 3, and then the clamping spring 20 of the spool and spool 19. Having unscrewed the fastening screws, remove the damper 11, axle 12 and spring 9 of the primary chamber. Unscrew the nut for fastening the levers on the axis of the throttle valve of the secondary chamber and remove the levers 5 and 7 with the spring 6. Remove the valve 11 and the axis 10 of the secondary chamber.
Clean and wash parts with gasoline or acetone. Check parts, replace damaged parts with new ones.