Step by Step on How to Tune Your Carburetor
1. Remove the engine air filter and housing from the engine to access the carburetor.
2. Adjust the air fuel mixture.
- You will use a flat head screwdriver to adjust the air fuel mixture.
- The screws are responsible for controlling the amount of fuel that enters the engine if they are improperly adjusted the engine will underperform.
3. You will observe the engines condition after the engine has been started and allowed to warm up to temperature.
4. Readjusting the air fuel mixture screw.
- Turning this adjustment screw clockwise (in) reduces the amount of fuel. Turning the screw counterclockwise (out), increases the amount of fuel delivered to the engine.
- It is important to make changes in small increments such as a quarter a turn.
- Back the adjustment screws off until the engine is running slightly lean.
- Tip: When the engine is running slightly lean the rpm will drop, the engine will begin to run rough, pop and sputter, until it stalls.
- Back off the mixture screw until the engine just begins to display symptoms of a lean mixture, and then tighten them down, in quarter turn increments, until the engine runs smoothly.
- Your throttle response should also be crisp and responsive. The engine should rev smoothly and quickly as soon as you apply throttle.
- The idle mixture screw controls the air fuel mixture at idle speed, and often is located near the throttle plate.
- Adjust it until the engine is idling smoothly, with no misfires or shakes, and at the proper speed.
- Making the air fuel mixture adjustment, back the idle mixture screw off into a lean condition, and then adjust it in quarter turn increments, until the desired idle speed is achieved.
8. Reinstall the air filer and test drive the vehicle.
- Take note of any changes in the vehicle’s power output, throttle response, and fuel consumption. If need be, go back and make any required adjustments, until the vehicle is running smoothly.