Inspect the fuel line. Ensure the fuel line is free of kinks or restrictions, allowing fuel to flow freely to the carburetor. If the fuel line is kinked or damaged, replace it with a new one.
Ensure the fuel tank vent is clear. If the fuel tank vent is blocked, it can create a vacuum in the tank, preventing fuel from flowing to the carburetor. To check the fuel tank vent, remove the gas cap and blow air through the vent. If the vent is blocked, clear it with a wire or compressed air.
Adjust the carburetor float level. If the carburetor float level is too low, it will not allow enough fuel to enter the carburetor and can cause the engine to run lean. To adjust the carburetor float level, refer to the service manual for your specific minibike model.
Check the carburetor jets. If the carburetor jets are clogged or too small, they will restrict the flow of fuel to the engine and can cause it to run lean. To check the carburetor jets, remove them from the carburetor and inspect them for dirt or debris. If the jets are clogged, clean them with a carburetor cleaner. If the jets are too small, you may need to replace them with larger ones.
Ensure the spark plug is correctly gapped. If the spark plug gap is too wide or too narrow, it can cause the engine to run lean. To check the spark plug gap, remove the spark plug and measure the gap between the electrodes with a feeler gauge. Adjust the gap to the specification listed in the service manual for your minibike model.
