To find the cause of the malfunction, disconnect the hose from the discharge pipe 1 (rice. 2-78) and using the lever 8 for manual fuel pumping, check whether fuel is supplied. If there is no fuel, then disconnect the hose from the suction pipe 4 and check whether a vacuum is created at the outlet of this pipe. If there is a vacuum, the fuel lines or the fuel fine filter may be damaged or clogged. If there is no vacuum, then the pump is faulty.
Dismantling, cleaning and checking parts
To disassemble the pump, unscrew the cover fastening bolt 5, remove the cover and filter 2. Then unscrew the screws securing the housing to the bottom cover, separate them, remove the diaphragm assembly and the spring. Rinse all parts with gasoline and blow with compressed air.
Check the integrity of the pump springs. Check for valve sticking Check the diaphragms. They should not be cracked or hardened.
After checking, replace any worn or damaged parts with new ones. Always replace pump gaskets with new ones and lubricate with a thin layer of grease before installation.