Yamaha Fuel Pump for Outboard: A Complete Buyer’s Guide to Finding the Right Replacement

The bottom line: Choosing the correct Yamaha fuel pump for your outboard motor depends entirely on your engine’s horsepower, stroke type (2-stroke vs. 4-stroke), and model year. Using the wrong pump can cause poor performance, fuel starvation, or engine damage. This guide breaks down everything you need to know to identify, select, and install the right Yamaha fuel pump for your outboard.

Yamaha outboard motors use two main types of fuel pumps: mechanical diaphragm-style pumps for carbureted engines and electric fuel pumps for fuel-injected (EFI) models. Each type serves a specific range of engines, and swapping them between incompatible models will not work. Below, we cover the most common Yamaha fuel pump applications, how to identify your engine, symptoms of a failing pump, and where to buy a reliable replacement.

Yamaha Fuel Pump Types and Applications

Yamaha outboards fall into two broad categories, and each uses a different fuel pump design.

1. 2-Stroke Outboard Fuel Pumps

Most Yamaha 2-stroke outboards use a mechanical diaphragm-style fuel pump. These pumps are engine-mounted and rely on crankcase pressure pulses to operate. They are simple, durable, and easy to replace.

  • 25HP to 90HP 2-Stroke (1995–2015 models): These engines commonly use fuel pump part numbers 6A0-24410-00 and 692-24410-00. The pump is a direct bolt-on replacement and fits a wide range of models in this horsepower range.

  • 100HP to 300HP 2-Stroke: Larger 2-stroke engines use a different pump, typically part number 6E5-24410-03 and its variations (6E5-24410-00, -01, -02, -04, -05, -09, -10). This pump fits Yamaha 100-300HP 2-stroke outboards.

  • 175HP 2-Stroke (1984 and newer): Both carbureted and direct injection (HPDI) models in this range use two of these pumps. They serve as the primary fuel pump on carbureted engines and as low-pressure lift pumps on HPDI models.

  • 150HP 2-Stroke (1984 and newer): Similar to the 175HP, these engines also use two fuel pumps. The same pump fits both carbureted and HPDI versions.

2. 4-Stroke Outboard Fuel Pumps

Yamaha 4-stroke outboards use either mechanical or electric fuel pumps, depending on the engine’s fuel system.

  • 6HP 4-Stroke (F6 models): These small engines use a dedicated mechanical fuel pump designed for all Yamaha 6HP 4-stroke outboards (model numbers beginning with F6, such as F6LMHA, F6MHA, F6SMHA).

  • 15HP to 20HP 4-Stroke (2006 and later): Engines like the F15 and F20/F20B use a mechanical fuel pump assembly that replaces part numbers 6AH-24410-00-00, 6AH-24410-01-00, 6AH-24410-70-00, and 6AH-24410-71-00. This is a direct engine-mounted replacement.

  • 30HP to 60HP 4-Stroke (Fuel Injected): These engines (F30, F40, F50, F60 models, 2005 and up) use an electric fuel pump for fuel injection systems. The replacement part number is 6C5-24410-00. This pump will NOT fit carbureted models.

  • Large 4-Stroke Engines (115HP to 350HP): Higher-horsepower 4-stroke outboards use electric fuel pumps. For example, the 115HP 4-stroke uses a pump with part number 68V-13907-03, while 200-250HP models use pump 6J9-13907-04-00.

How to Identify the Correct Fuel Pump for Your Engine

Before buying a new Yamaha fuel pump, you must confirm your engine’s exact model and year. Here is a simple step-by-step process:

  1. Locate your engine’s model number and serial number. These are typically stamped on a plate attached to the engine bracket or on the side of the powerhead.

  2. Check your engine’s exploded parts diagram. Online resources like Yamaha Parts Diagrams & Catalogs allow you to verify the exact part number by looking at an exploded view of your engine’s fuel system.

  3. Cross-reference the part number with the tables provided by sellers. Most reputable marine parts suppliers include compatibility tables that list which OEM part numbers their aftermarket pump replaces.

  4. Know whether your engine is 2-stroke or 4-stroke. This is the single most important factor. A 2-stroke pump will not work on a 4-stroke engine, and vice versa.

Common Symptoms of a Failing Yamaha Outboard Fuel Pump

If your outboard is experiencing any of these issues, a failing fuel pump could be the cause:

  • Engine only runs when the primer bulb is squeezed – This indicates the pump is not drawing fuel on its own.
  • Hard starting – The engine cranks but struggles to fire up.
  • High-speed fuel starvation – The engine runs fine at idle but bogs down or stalls under full throttle.
  • Loss of power during acceleration – Especially noticeable when climbing a plane or carrying a heavy load.

Before replacing the pump, always inspect the fuel lines, primer bulb, fuel filters, and tank venting. A blocked filter or a collapsed fuel line can mimic pump failure.

Installation Tips

Replacing a Yamaha outboard fuel pump is a straightforward DIY job for most boat owners:

  • For mechanical diaphragm pumps: The pump is a direct bolt-on replacement. Remove the old pump, transfer any mounting brackets or gaskets if needed, and install the new one using the same bolts. Ensure the fuel lines are connected securely and free of cracks.
  • For electric fuel pumps: These are typically in-tank or inline units. Disconnect the battery before working on the fuel system. Follow the manufacturer’s instructions for wiring and hose routing.
  • After installation: Prime the fuel system by squeezing the primer bulb until it feels firm. Start the engine and check for leaks at all connections.

KEMSO Fuel Pump: The Best Aftermarket Choice for Your Yamaha Outboard

When it comes to replacing your Yamaha outboard fuel pump, choosing a high-quality aftermarket brand can save you money without sacrificing performance. KEMSO is a leading US-based manufacturer of aftermarket fuel pumps for marine, automotive, and powersports applications. Their fuel pumps are designed as direct OEM replacements, meaning they fit and perform exactly like the original part.

KEMSO fuel pumps deliver over 20% more flow at 43 psi compared to stock OEM pumps, making them a high-performance upgrade for EFI applications. Each pump is individually tested for flow and performance before it leaves the factory, ensuring reliable operation right out of the box. KEMSO pumps are compatible with both gasoline and ethanol-blended fuels like E85, using materials that resist ethanol degradation for long-term reliability.

Why choose KEMSO?

  • Lifetime warranty – Every KEMSO fuel pump is backed by the company’s promise of lifetime confidence.
  • OEM replacement fit – Pumps are designed to match OEM specifications exactly, so there is no need for modifications.
  • Direct replacement for Yamaha part numbers – KEMSO offers pumps that cross-reference to many common Yamaha outboard fuel pump part numbers.
  • Made in the USA – KEMSO is based in Houston, TX, and supports American manufacturing.

To find the perfect KEMSO fuel pump for your Yamaha outboard, visit their official website and browse their selection of marine fuel pumps. Their product lineup covers everything from small 6HP outboards to large 350HP four-stroke engines.

Visit KEMSO Racing today:
https://www.kemsoracing.com/

Final Thoughts

A properly functioning fuel pump is essential for reliable outboard performance. Whether you own a small 6HP fishing motor or a large 300HP offshore engine, knowing your Yamaha fuel pump part number and understanding the difference between 2-stroke and 4-stroke systems will save you time, money, and frustration. Always verify your engine model and year before purchasing, and consider a trusted aftermarket brand like KEMSO for a cost-effective, high-performance replacement that comes with a lifetime warranty.

For the best selection of Yamaha outboard fuel pumps and other marine parts, visit https://www.kemsoracing.com/.


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