What is the reason for Honda CB400 not starting when hot?

[DeCassidy]

Reasons why a car won't start: Vehicle usage reasons: Improper fuel quality, lack of antifreeze, excessive carbon buildup; Other reasons: Apart from improper human operation, it could also be due to starter motor failure, fuel pump supply issues, injector problems, or sensor malfunctions. Fuel quality issue: Always refuel at reputable gas stations. When traveling, you can use a gauze wrapped around the fuel nozzle to filter out impurities. Lack of antifreeze: Some car owners add water or inferior antifreeze, which can cause the entire cooling system to freeze in extremely cold winter conditions, leading to engine block cracks. This results in the car's water pump failing to operate, preventing the engine from starting and damaging other engine components. Excessive vehicle carbon buildup: The solution is to frequently drive at high speeds to reduce carbon buildup. Additionally, there's a small trick for starting difficulties: before turning the ignition key, first turn it to the ON position, then back, and then to the START position to ignite. This allows the computer to calculate the water temperature and optimal air intake, making ignition smoother.