Mikuni Bs25 Carburetor Diagram Patched [better] May 2026
The Mikuni BS25 is a constant-velocity (CV) carburetor frequently used in 150cc 4-stroke engines, such as the GY6 series. It is designed to provide smooth acceleration and fuel efficiency compared to mechanical slide carburetors. Key Specifications Bore Size: 25mm inner diameter on the intake side. Outer Diameter: 34mm (intake) and 42mm (air filter side).
- A labeled vector-style diagram (SVG) showing the exact patched locations and measurements, or
- A printable step-by-step repair checklist with torque values and part numbers.
2. The Taped Vacuum Port
The BS25 has a small barbed fitting for the fuel petcock (auto fuel valve). mikuni bs25 carburetor diagram patched
- Improved engine performance: By fine-tuning the carburetor to specific engine configurations or riding conditions, riders can experience improved power delivery, throttle response, and overall engine performance.
- Enhanced fuel efficiency: A well-tuned carburetor can optimize fuel flow, leading to improved fuel efficiency and reduced fuel consumption.
- Increased reliability: By ensuring the carburetor is properly tuned, riders can reduce the risk of engine damage caused by improper air-fuel mixtures.
Tuning & Maintenance: For specific tuning curves and effectiveness of parts (like the pilot jet vs. main jet ranges), the Mikuni Power Resources page offers functional charts that explain how adjustments impact performance. Key Specifications for BS25 Measurement Intake ID Intake OD Air Filter ID Air Filter OD Mikuni Carburetor Catalog The Mikuni BS25 is a constant-velocity (CV) carburetor