How does the centrifugal clutch (primary clutch) operate in a semi-automatic underbone motorcycle (e.g., Honda Wave)?

1. As engine speed increases, centrifugal force throws weighted clutch shoes outward to engage the clutch outer drum, transferring power to the secondary clutch.
2. It requires the rider to pull a lever on the handlebar to disengage the clutch shoes.
3. It uses engine oil pressure to press the friction plates together electrically.
4. It stays permanently locked and only disengages when the engine is turned off.