The air filter is dirty and clogged. This situation basically means that the engine's intake valve is blocked and can no longer breathe inside. If the air filter is disposable, it must be replaced with a new one. Of course, some are used multiple times and can be cleaned and put back. In this way, the EFI motorcycle can be used normally.
The occurrence of such intermittent misfires on scooters is usually caused by a short circuit in the magneto stator coil or in the trigger coil. Additionally, this phenomenon can also occur if there is a problem with the igniter. According to the principle of easy first, then hard, first replace the igniter with a qualified igniter of the same model. If the fault cannot be eliminated, check the magneto stator. However, this is not evident from the looks and everything will be. normal when the car is cold, so generally only the tests can be replaced by new parts.