Brand new 2FastMoto OEM reproduction 4 piece Honda CV (Constant Velocity) Carburetor Accelerator Pump Kit. When the motorcycle throttle opens far enough, it loses vacuum in the carb throat as it transitions from the low speed circuit (pilot circuit/throttle valve) to the high speed circuit (needle jet/jet needle/main jet).The momentary lag during this transition can cause a lean condition. Your motorcycle's throttle linkage activates the carburetor accelerator pump, which adds more fuel during this momentary lag to correct the lean condition, helping to prevent hesitation. Worn out components in your motorcycle's accelerator pump can lead to poor performance of the carburetor. Our high quality 4 piece 2FastMoto Accelerator Pump Kit replaces the main components in your motorcyle's accelerator pump that can wear out over time.
Replaces Honda OEM Numbers: 16021-413-751, 16021-438-671, 16021-463-004
Replaces K&L Number: 18-2808
Diagphram with 54.1mm long rod
O-ring for passageway