1. Preparation:
Before starting, ensure the engine is cool and turned off. Disconnect the battery's negative terminal to prevent any electrical issues during the process.
2. Fuel Preparation:
Turn the fuel valve to "OFF" and drain any remaining fuel from the carburetor bowl. This step is crucial to avoid fuel spills.
3. Remove the Air Filter:
Locate the air filter housing on the carburetor. Depending on the model, it may be attached with screws or a clamp. Remove the air filter carefully without damaging it.
4. Find the Adjustment Screws:
On the sides of the carburetor, you will find two adjustment screws: the idle speed screw (usually marked "Idle") and the air mixture screw (commonly labeled as "Air" or "Mixture").
5. Idle Speed Screw Setting:
Turn the idle speed screw clockwise until it stops gently. This ensures that the screw is fully seated. Then, turn it counterclockwise exactly 2.5 turns. This sets the idle speed screw to the factory-recommended setting.
6. Air Mixture Screw Setting:
Similarly, locate the air mixture screw and turn it clockwise until it stops gently. Once seated, turn it counterclockwise approximately 2 turns to set the air mixture screw to the factory-recommended position.
7. Reinstall the Air Filter:
Carefully put the air filter back in place and secure it with the screws or clamp you removed earlier. Ensure the air filter is properly seated and aligned.
8. Turn on the Fuel Valve:
Switch the fuel valve back to the "ON" position and visually inspect the carburetor for any fuel leaks. If there are no leaks, proceed to the next step.
9. Start the Engine:
Reconnect the battery's negative terminal and try starting the motorcycle. If needed, adjust the idle speed screw slightly with the engine running. The ideal idle speed should be around 1400-1500 RPM for the Honda CG 125.
10. Test the Settings:
Take the motorcycle for a test ride and observe its performance. Check for proper acceleration, smooth idling, and absence of any hesitation or surging. Make minor adjustments to the idle speed and air mixture screws if necessary to achieve optimal performance.
11. Final Adjustments:
After riding for some time, allow the engine to cool down and then give it a final recheck. Fine-tune the idle speed and air mixture screws as required to achieve the best possible performance and fuel economy.
12. Confirm Correct Settings:
Verify that the idle speed and air mixture screw settings align with the factory-recommended values. If they match, the carburetor has been successfully reset.
Remember that carburetor settings can vary slightly depending on the motorcycle's specific condition, climate, and altitude. If you encounter any issues or have doubts, consult the Honda CG 125 Service Manual or seek assistance from an experienced mechanic.
