Yamaha - Idler Gear Internal Gear System 6AW-8183T-00-00. Overview. The idler gear isn't the biggest piece in the system, but it plays a key role in keeping everything turning the way it should. When it's working right, you get smooth, quiet operation without even thinking about what's happening inside. Once it starts to wear, though, you'll hear it-usually before you see anything else. It's one of those internal parts that helps keep timing and movement consistent under real engine load.. Key Features. Smooth Gear Transition - Helps transfer motion between gears for consistent internal operation.. Precision Tooth Alignment - Designed for proper meshing to reduce noise and uneven wear.. Durable Gear Build - Handles continuous rotation and load inside the engine system.. OEM Fit Accuracy - Matches Yamaha specifications for correct placement and performance.. Engine & Boat Compatibility. Designed for Yamaha outboard engines utilizing this idler gear within internal gear systems. Commonly