Product Description
Increased Airflow: Koso 28mm Performance Throttle Body
Maximize the volumetric efficiency of your 5-speed engine with the Koso 28mm Throttle Body. Specifically engineered for the 2022+ Honda Grom and Monkey 125, this upgrade replaces the restrictive factory unit to allow a higher volume of air into the combustion chamber. The result is a sharper throttle response, improved mid-range pull, and increased top-end power, making it an essential foundation for any performance build.
Technical Performance Features
- Optimized 28mm Bore: Provides a significant increase in airflow over the stock throttle body without sacrificing the intake velocity needed for low-end torque.
- Precision Machined Internal: Features a smoothed internal bore and a high-tolerance butterfly valve to eliminate turbulence and ensure linear throttle delivery.
- OEM Sensor Compatibility: Designed to accept your factory MAP, IAT, and TPS sensors for a clean, integrated installation that maintains ECU communication.
- High-Flow Intake Path: When paired with the Koso Intake Manifold, this setup creates a streamlined "straight-shot" air path into the cylinder head.
Comprehensive Fitment Guide
This throttle body (SKU: 128-51) is designed exclusively for the 5-speed (long-stroke) Honda 125cc engine found in:
| Model Series | Year Compatibility |
|---|---|
| Honda Grom 125 (ABS & Non-ABS) | 2022 – 2026+ (5-Speed Models) |
| Honda Monkey 125 | 2022 – 2026+ (5-Speed Models) |
Technical Specifications
- Bore Diameter: 28mm
- Material: Die-Cast Aluminum Alloy
- Manufacturer MPN: DY640000
- Required Modification: ECU Reset or Fuel Controller highly recommended
Pro-Tuning Note: To achieve the full performance benefits, this throttle body should be used in conjunction with the Koso 23-29mm Intake Manifold DP640000. After installation, a "TP Sensor Reset" is required to ensure the ECU recognizes the new butterfly position at idle.
Part Number: 128-51
Manufacturer: Koso Taiwan
