I have changed to twin clutch on BNR34, but sound is generating from the drive train during idling and accelerating. Is this a malfunction?
This is not a malfunction.
Genuine flywheel for the BNR34 has special structure with a built-in damper.
This damper absorbs the fluctuation of the engine revolution, reducing the sound and vibration generated in the drive train, such as rattling sound of the transmission gear tooth, etc.
By replacing the genuine flywheel to other flywheel, the damper is removed also, so you will start to feel the sound and vibration generated in the drive train.
EXEDY is selling the clutch system “CARBON-D” that removed this “discomfort feeling” completely.
This product has a damper mounted on the center hub, reducing the sound and vibration from the drive train. This is a racing clutch that sought quietness and comfort.
Please try it.