To disassemble the pump, unscrew the cover fastening bolt 5 (see fig. 2-79), remove the cover and filter 2. Then unscrew the screws securing the housing to the bottom cover, separate them, remove the diaphragm assembly and spring. Rinse all parts with gasoline and blow with compressed air.
Check the integrity of the pump springs. Check for valve sticking. Check diaphragm integrity. 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.