A loud bang sound while accelerating followed by the motorcycle not starting could indicate a few potential issues. Here are some possible causes:
Backfire: A backfire occurs when unburned fuel ignites in the exhaust system or intake manifold instead of in the combustion chamber. This can be caused by a variety of factors, such as an overly rich fuel-air mixture, an ignition timing issue, or a malfunctioning exhaust system. The backfire could potentially damage components like the exhaust system or the air filter.
Ignition system problem: If there is an issue with the ignition system, such as a faulty spark plug, ignition coil, or ignition timing, it can lead to misfires or a complete lack of spark. This can prevent the engine from starting.
Fuel system problem: Problems in the fuel system, such as a clogged fuel filter, a malfunctioning fuel pump, or a stuck open fuel injector, can cause an imbalance in the air-fuel mixture. This can lead to a backfire and subsequent engine starting issues.
Engine mechanical issue: In some cases, a loud bang followed by the engine not starting could indicate a more serious mechanical problem, such as a broken valve, piston, or connecting rod. These issues typically require professional diagnosis and repair.
In any case, it is best to have your motorcycle inspected and diagnosed by a qualified mechanic. They can examine the motorcycle, perform necessary tests, and provide an accurate diagnosis of the problem. Avoid attempting to start the motorcycle repeatedly as it may cause further damage.