Yes, overfueling can be bad for your motorcycle. Running a motorcycle with an excessively rich fuel-air mixture can have several negative effects:
Reduced Performance: An overly rich mixture can result in poor combustion and incomplete fuel burning. This can lead to reduced engine power and throttle response, resulting in sluggish performance.
Increased Fuel Consumption: When the fuel mixture is too rich, more fuel is being injected into the combustion chamber than necessary. This excess fuel is not efficiently burned, resulting in increased fuel consumption and reduced overall fuel efficiency.
Fouled Spark Plugs: Rich fuel mixtures can cause spark plugs to become fouled or carbonized. The unburnt fuel deposits on the spark plugs can inhibit proper ignition, leading to misfires, rough idling, and difficulty starting the engine.
Increased Emissions: An overly rich fuel mixture can contribute to increased emissions of hydrocarbons (HC) and carbon monoxide (CO). This can be harmful to the environment and may result in the motorcycle failing emissions tests or not meeting regulatory requirements.
Potential Engine Damage: Extended periods of running with a rich fuel-air mixture can cause damage to the engine components. The excess fuel can wash away the lubricating oil film on the cylinder walls, leading to increased wear and reduced engine lifespan. It can also cause damage to the catalytic converter, if equipped.
It's important to ensure that your motorcycle's fuel system is properly tuned to maintain the correct air-fuel ratio for optimal performance, fuel efficiency, and longevity. If you suspect your motorcycle is overfuelling, it is advisable to have it inspected and tuned by a qualified mechanic or motorcycle technician.