Introducing the Holley 4500 1050 CFM 3 CIR - Hard Black Marine carburetor, a game-changer for your high-performance marine engine! This innovative product features a patent-pending GEN 3 main body that stands 5/16" taller than its predecessor. This extra height paves the way for larger radius air entries, meticulously optimized using Computational Fluid Dynamics (CFD) software to ensure a seamless flow into the newly designed, fully machined big bore venturi.

What’s more, the main body comes equipped with an integrated idle bypass valve, allowing you to fine-tune your idle settings while keeping the relationship between the throttle plate and transfer slot just right. Plus, the extended air cleaner flange makes attaching an air scoop a breeze when you use the compatible air scoop adapter.

The GEN 3 carburetor is designed with high-capacity fuel bowls that boast 20% more fuel capacity, effectively eliminating any risk of starvation. It also includes an integrated fuel shelf to minimize aeration and internal baffling to keep fuel slosh under control.

Crafted entirely from aluminum, this carburetor is lightweight and durable. It features 12-hole billet booster inserts for superior atomization, fully tunable billet metering blocks, adjustable external linkage, and convenient throttle position sensor mounting points. The knurled curb idle screws allow for easy adjustments by hand. Each calibration has been rigorously dyno tested to ensure you get proven performance!

Important Downloads:

• Instructions for Part# 0-80903HBM

Features:

• All aluminum construction saves 3.8 lbs compared to original models (28% weight savings)
• Gray anodized finish paired with black anodized billet aluminum metering block and booster inserts
• Engineered for use on high horsepower marine engines
• Fully machined from venturi throat to throttle bore, ensuring reliable and repeatable performance
• Integrated idle bypass valve for idle adjustments while maintaining the correct throttle plate to transfer slot relationship
• 12-hole billet booster inserts for exceptional atomization and responsive throttle
• Durable metering blocks with true gasket sealing and fully adjustable settings (emulsion bleeds, power valve channel restrictors, and idle feed restrictors)
• Dual 50cc accelerator pumps deliver the perfect amount of fuel from idle to full throttle
• Fuel bowls with 20% more capacity and internal baffling to control slosh
• Clear sight windows on both sides of the bowls for safe and easy fuel level checks
• Convenient drain plug located at the front center of the bowl for hassle-free emptying
• 8 (o-ringed) inlet threads for versatile plumbing options, allowing for connections from either side
• Factory-ready TPS mounting points compatible with data acquisition systems (Holley TPS P/N 534-214 available)
• Knurled primary and secondary curb idle screws for tool-free adjustments
• Contoured hex head squirter screws for optimized airflow
• Fully adjustable stainless steel external linkage for customizable throttle activation
• 100% wet-flow tested by Holley technicians, ensuring it arrives ready to run!
• J-Style vent tubes

Specifications:

• Barrels: 4
• Billet Color: Hard Core Gray with Black
• Booster: Annular
• CFM: 1050
• Choke: None
• Circuit: 3
• Emission Code: 4
• Finish: Hard Core Gray
• Fuel: Gasoline
• Fuel Inlet: Dual
• High Speed Air Bleed: 43
• Idle Air Bleed Size: 65
• Intermediate Air Bleed: 71
• Marine Engine Size: Universal
• Material: Aluminum
• Model: 4500
• Needle and Seat Size: 120;120
• Primary Main Jet: 84
• Primary Power Valve: 6.5
• Primary Pump Nozzle Size: 35
• Product Type: Carburetor
• Secondaries: Mechanical
• Secondary Main Jet: 84
• Secondary Pump Nozzle Size: 35
• Supercharged Application: No
• Throttle Bore: 2.000 inch
• Venturi Size: 1.690 inch
• Warranty: Limited 90 Day

Notes:

• New or modified fuel lines are necessary if you're replacing an existing Holley Dominator 4500 series carburetor. The previous bowl machining was 7/8-20, and Aluminum Ultra Dominator carburetors come assembled with -6AN to SAE 8 port fittings. The center-to-center fuel inlet measurement for the 0-80903HBM is now 11.5".