Making sure you're getting spark and learning the tips and tricks needed to keep your engine in top shape will improve your motor performance and keep it running longer and more consistent.
This video will teach you how to properly test your magneto loop set, electron ignition coil (CDI), and spark plug with an OHMs meter on your motorized bicycle:
Video Instructions Here- Ohms Testing
Video Instructions Here- Improving Magneto Contact Point
Check blue and black wire connections coming from the motor to the connections to the CDI module. If secure and tight, remove the kill switch wire completely and see if the spark plug now has a spark. To check for spark, remove the spark plug from the head of the engine, with the spark plug making contact with cylinder fins, spinning rear wheel, and see if the spark is generating. If the spark plug now has a spark, inspect kill switch wires for unwanted ground. If the spark plug still has no spark, proceed to the next step.
Check magneto coil with an OHMs meter. Set OHMs meter to 2K or 2000 setting. Place OHMs meter positive and negative contacts to contact points on top of the magneto. Ohms meter reading should read 300 to 380 ohms across the blue and black contact points. Also, check for loose contacts and/or high corrosion. Then CDI should be between 6 to 8 ohms. If an open or shorted magneto coil is found, replace the magneto coil. If the magneto coil is good, it is possible that the magneto is not properly grounded to the engine due to the epoxy coating on the magneto. Using fine grit sandpaper, lightly sand the underside of the magneto before re-installing the magneto.