Why Can't a Motorcycle Engine Start?
1 Answers
Motorcycle engine failure to start can be caused by abnormal spark plug ignition, engine cylinder scoring, loss of magnetism in the motorcycle generator flywheel magnet, or poor contact between the ignition wire and the generator. When encountering difficulty starting or failure to start, it is essential to promptly troubleshoot to avoid unnecessary hazards. Abnormal Spark Plug Ignition: If the air gap between the magneto and the charging coil core is too large (the normal gap should not be less than 0.80mm), it can cause abnormalities when cutting the magnetic lines of force. Additionally, friction between the motorcycle flywheel and the charging coil core can cause a sharp rise in coil temperature, reducing insulation performance. Both scenarios can lead to abnormal ignition, potentially damaging the spark plug. Check if the spark plug has excessive carbon buildup and replace it promptly if necessary. Engine Cylinder Scoring: Cylinder scoring is a common issue during engine operation, leading to insufficient cylinder pressure, which prevents the motorcycle from starting normally or causes it to stall. After cylinder scoring occurs, professional repair is required, involving the replacement of critical components such as the cylinder liner, piston, and piston rings. Loss of Magnetism in Motorcycle Generator Flywheel Magnet: Most motorcycle engine generator magnetic fields consist of two or more sub-magnetic fields. However, when the magnet loses its magnetism, the magnetic field strength of each sub-field varies, resulting in asymmetric adjacent magnetic field strengths and significant current fluctuations. Professional repair shops should inspect and service the generator. Poor Contact Between Ignition Wire and Generator: Loose connections between the generator's output terminal and the ignition coil's input terminal can lead to poor contact, causing "jumpy" current fluctuations. Disordered current severely disrupts the spark plug's normal ignition function. Inspect whether the rubber sleeve connected to the ignition coil's secondary terminal and the protective sleeve of the terminal are sealed. Also, check for loose metal connectors inside. It is advisable to seek professional assistance.
