Yamaha - Gear, idler - 6AW-8183T-00-00Yamaha Idler Gear Internal Gear System 6AW 8183T 00 00 Overview The idler gear isnt the biggest piece in the system, but it plays a key role in keeping everything turning the way it should. When its working right, you get smooth, quiet operation without even thinking about whats happening inside. Once it starts to wear, though, youll hear itusually before you see anything else. Its one of those internal parts that helps keep timing and movement