Carter BBD Accelerator Pump Plunger - Leather cup is designed to withstand today's fuel with alcohol / ethanol.
Carter BBD carburetors
Carter OEM # 64-413S
Over all length: 2.35"
Pump Cup diameter: 5/8"
Stem Diameter: 1/8"
Instructions when replacing accelerator pumps:
It is very important that the accelerator pump bore is completely smooth. Today's fuels with ethanol have less lubrication and demand super smooth pump bore surfaces. Polish pump bore with crocus cloth as required. Rough pump bore surfaces will cause pump cup to stick to bore and tear or dislodge from plunger assembly.
Do not allow carburetor cleaner come in contact with pump assembly.
Coat outer edges of leather pump cup with a light coating of oil before assembly.
Long term vehicle storage:
If vehicle is dormant and fuel bowl is allowed to go dry, pump cup has a much higher chance of sticking to pump bore. If bowl has run dry, fill fuel bowl with fuel before pumping accelerator pump assembly.