Yamaha - Main Nozzle Carburetor Fuel Metering Component 7DH-E495H-4C-00. Overview. The main nozzle is one of those parts that really shows its impact when you're running at higher speeds. If it's clogged or worn, the engine just won't pull the way it should. I've seen motors struggle under load or feel flat on top end just from this piece being off. When it's clean and correct, the engine delivers smooth, steady power all the way through.. Key Features. • High-Speed Fuel Delivery - Controls fuel flow through the carburetor at mid to full throttle.• Precision Metering Design - Engineered to deliver accurate fuel distribution for consistent performance.• OEM Fit and Function - Matches factory specifications for proper installation and operation.• Supports Strong Engine Output - Helps maintain smooth acceleration and reliable top-end performance.. Engine & Boat Compatibility. Designed for Yamaha outboard engines equipped with carbureted fuel systems that utilize a main nozzle for fuel del