float mechanism. The float must not be damaged or distorted in any way. The mass of the float should be 11-13 g. The sealing surfaces of the needle valve and its seat must not be damaged that violate the tightness of the valve. The valve must move freely in its seat, and its ball must be free to mix and not hang. Replace defective parts with new ones.
Carburetor cover. Remove dirt and oil from the cover and all openings and channels. Wash the cap in gasoline or acetone and blow with compressed air. Inspect the sealing surfaces of the cover. If damage is found, replace the cover with a new one.
Starting device. Clean all parts of the starting device, wash with gasoline and blow with compressed air. Inspect parts, replace damaged parts with new ones.
Jets and emulsion tubes. Clean jets and emulsion tubes from dirt and tar deposits. Rinse them with acetone or gasoline and blow with compressed air.
Warning. It is not allowed to clean the jets with a metal tool or wire, and also wipe the jets and other parts of the carburetor with cotton, cloth or rags, as the villi can clog the fuel-emulsion path. In case of severe clogging, you can clean the jets with a soft wood needle moistened with acetone.
Carburetor shut-off valve (pic. 2-98). In case of interruptions in the operation of the valve, it is necessary to check for jamming of the valve needle, and also check the resistance of the coil, which should be 150-160 ohms at 20°C. If it differs from the nominal value, replace the shut-off valve.
Pic. 2-98. Carburetor shut-off valve: 1 - idle fuel jet; 2 - needle; 3 - sealing ring; 4 - valve body; 5 - contact plate; 6 - coil; 7 - coil casing; 8 - plug; A - calibrated jet hole; B - hole for fuel to exit into the emulsion channel of the carburetor idle system
Carburetor body. Clean the body of dirt and oil. Wash the body and its passages with petrol or acetone and blow with compressed air. If necessary, clean the channels and emulsion wells with special reamers. Inspect the sealing surfaces of the body, if they are damaged, replace the body with a new one.
Accelerator pump. Clean the parts of the pump, wash them and blow them with compressed air. Check the ease of movement of the ball in the screw valve 9 (rice. 2-96) and condition of sealing surfaces and gaskets. Check the ease of movement of the moving parts of the pump (lever, roller, diaphragm parts). Eating is not allowed. The diaphragm must be intact, without deformation. Replace damaged parts with new ones
Pneumatic throttle valve of the secondary chamber. Clean parts, rinse and blow with compressed air. Check the condition of the diaphragm, it should not be damaged.
Throttle body and its parts. Clean the parts and wash them with gasoline or acetone. Inspect parts, replace damaged parts.