1. Battery: Check the battery's voltage; it should be around 12.6 volts when fully charged. If it's low, charge or replace the battery. Also Clean and tighten the battery terminal connectors to ensure a good electrical connection.
2. Fuel Supply: Check the fuel tank to make sure it has enough gas. Make sure the fuel petcock is open and that fuel is flowing to the carburetor.
3. Spark Plugs: Remove the spark plugs and check their condition. Clean any deposits off of the electrodes, and make sure the gap is set to specifications (check the owner's manual). If the plugs are worn or damaged, replace them.
4. Air Filter: Check the air filter to ensure that it is clean and free of obstructions. A dirty or clogged air filter can restrict airflow to the carburetor and cause starting issues.
5. Fuel Filter: If your bike has a fuel filter, inspect it for blockages or restrictions. A dirty or clogged fuel filter can restrict the flow of fuel to the engine.
6. Electrical Connections: Check all of the electrical connections, including the spark plug wires, coil wires, and ignition switch. Make sure all connections are tight and free of corrosion.
7. Fuel Lines: Inspect the fuel lines for any damage, cracks or leaks. Ensure that the lines are properly connected to the fuel tank, carburetor, and fuel filter.
8. Carburetor: Clean and inspect the carburetor. Make sure the jets are clear and free of obstructions. Adjust the idle mixture screw as per the manufacturer's specifications to ensure proper fuel and air mixture.
9. Starter Solenoid: Test the starter solenoid to ensure that it is functioning properly. If the solenoid is defective, replace it.
10. Starter Motor: Check the starter motor, if the starter motor is weak or not receiving enough power, it may not be able to turn the engine over. Try bypassing the starter solenoid to test the strength of the starter motor.
If you have checked all of these things and your motorcycle still will not start, it's best to take it to a qualified mechanic for further diagnosis and repair.
