The issue you described with your Royal Enfield Classic 350 BS4, where the motorcycle turns off automatically while riding and the neutral light goes off, can have several potential causes. It's challenging to pinpoint the exact problem without a thorough inspection, but here are a few possibilities:
Electrical issue: The symptoms you described, such as the neutral light going off and the motorcycle shutting down, suggest a possible electrical issue. There may be a loose connection, a faulty ignition switch, or a problem with the electrical wiring. When the key is turned off and on again, the connection is momentarily restored, allowing the motorcycle to start.
Fuel system problem: It's also worth considering a potential issue with the fuel system. A clogged fuel filter, a malfunctioning fuel pump, or inadequate fuel flow could result in fuel starvation, causing the engine to shut down.
Ignition system malfunction: Faulty components in the ignition system, such as a failing ignition coil or spark plug, could cause intermittent engine shutdowns.
Engine overheating: If the engine is overheating, it could trigger an automatic shut-off mechanism to protect the engine from damage. In such cases, the cooling system, including the radiator and cooling fan, should be checked for proper functioning.
Given the complexity of diagnosing the exact issue remotely, I would strongly recommend consulting a qualified Royal Enfield mechanic or authorized service center. They will be able to perform a thorough inspection, conduct diagnostic tests, and identify the root cause of the problem based on the specific symptoms you're experiencing. They can then provide you with an accurate diagnosis and necessary repairs.