Yamaha - Carburetor Assembly 1 Fuel System Component 6J8-14301-12-00. Overview. When a carb starts acting up, you feel it right away-rough idle, hesitation, or just not running clean. I've replaced assemblies like this on plenty of Yamahas, and it's one of those upgrades that brings everything back into line fast. Once fuel flow is right, the engine settles down and responds the way it should. It's a dependable fix when the original carb has just worn out over time.. Key Features. Consistent Fuel Delivery - Provides steady fuel flow for smooth engine operation at all speeds.. Pre-Calibrated Assembly - Built to Yamaha specs for reliable performance right out of the box.. Durable Internal Components - Handles long-term exposure to fuel and engine vibration.. Factory-Spec Fitment - Ensures proper alignment and seamless installation.. Restores Engine Performance - Helps eliminate rough idle, hesitation, and power loss.. Engine & Boat Compatibility. Designed for Yamaha outboard engines with