Yamaha - Carburetor Repair Kit Fuel System Service 6H4-W0093-04-00. Overview. Carb issues usually show up when you're trying to get out on the water, not when it's convenient. I've seen plenty of Yamahas come back to life just by going through the carb the right way with a proper kit like this. When fuel delivery isn't clean, everything suffers-idle, throttle response, even starting. This is the kind of maintenance that keeps your motor running the way it should, especially if it's been sitting