Wash the parts of the float mechanism in gasoline and check their condition. The float must not be damaged. On the sealing surface of the needle valve and its seat, damage that violates the tightness of the valve is not allowed. The valve should move freely in its seat, and the ball should not hang. The mass of the float should not exceed 6.23 g. Defective parts are replaced with new ones.
Clean the carburetor cover and all holes and channels from oil and dirt. Rinse the lid in acetone or gasoline and blow it with compressed air. Inspect the sealing surfaces of the cover. If there is damage, replace the cover with a new one.
All parts of the starting device are cleaned, washed with gasoline and blown with compressed air. Inspect parts, replace damaged parts with new ones.
Jets and emulsion tubes are cleaned of dirt and resinous compounds, washed with acetone or gasoline and blown with compressed air. Do not clean the jets with a metal tool or wire, and do not wipe the jets and other parts of the carburetor with cotton, cloth or rags, as the villi can clog the fuel and emulsion channels. In case of severe clogging, you can clean the jets with a soft wood needle moistened with acetone.
Clean the carburetor body from oil and dirt. Rinse its channels with acetone or gasoline and blow with compressed air. If necessary, channels and emulsion tubes are cleaned with special reamers. Inspect the sealing surfaces of the body. If they are damaged or deformed, replace the case with a new one.
Clean the parts of the accelerator pump, wash with gasoline, blow with compressed air. Check the ease of movement of the valves and the movement of the moving parts of the pump (lever, diaphragm parts). Eating is not allowed. The diaphragm must be intact, without damage. Check the condition of the sealing surfaces and gaskets. Replace damaged pump parts with new ones.
Check the full length of the power economizer diaphragm pusher, including the pusher head. With a length of less than 6 mm, the diaphragm assembly with the pusher is replaced with new ones.
Check the operation of the locking mechanism of the second chamber, for which lever 5 (see fig. 15) air damper control is turned counterclockwise until the damper is completely closed. Then the throttle control lever 17 is turned until the throttle valve of the first chamber is fully opened. In this case, the throttle valve of the second chamber must remain in the closed position. Then turn the choke control lever until the throttle is fully open, and the throttle control lever until the throttle valves are fully open. If the throttle valve of the second chamber does not open at the same time, eliminate the malfunction. The reason may be that the lock lever of the second chamber is stuck or the spring of the lock lever is disconnected.