DEF Fuel Pump Kit for Kohler CH18-CH730 Engines — Direct-Fit Replacement with Adapters

DEF Fuel Pump Kit is a direct-fit replacement assembly designed to restore reliable fuel delivery on compatible Kohler small engines.

This kit from DEF replaces a range of Kohler OEM numbers and fits many CH- and CV-series lawn mower engines, giving you a complete fuel-pump solution in one box. It includes the pump assembly and the common adapters used on Kohler engines, so you can swap the old, failing unit for a freshly assembled pump without hunting for individual parts. Before ordering, verify the OEM reference or engine model against your machine to ensure compatibility.

Which Kohler part numbers and models does this DEF kit replace?

The DEF kit is built to replace numerous Kohler references, covering older and current part numbers used across small-engine applications. It lists direct equivalents so you can match it to the number stamped on your existing pump or the parts diagram for your engine.

• Replaces Kohler numbers including 24-393-12-S, 24-559-02-S, 24-559-05-S, 24-559-08-S, 24-559-10-S and related references.
• Covers several legacy codes such as 2439312-S, 2455902-S, 2455905-S and 2475734-S.
• Designed to substitute OEM pumps in many parts catalogs where those numbers appear.

How do I confirm fitment for my mower before I buy?

Confirming fitment is a quick two-step check: compare the part number stamped on the existing pump to the replacement list, and verify your engine model against the compatibility chart provided. If either matches, the kit should install without need for custom modifications.

• Check your engine plate for model codes like CH18, CH19, CH20, CH22, CH23, CH25, CH640, CH730.
• Match stamped OEM part numbers (for example 24-559-03-S or 24-393-12-S) to the DEF kit’s replacement list.
• When in doubt, consult the mower’s service manual or contact a dealer with your engine model and part number.

What’s included and how simple is installation?

The kit ships with the assembled pump and common adapters needed for direct replacement on compatible Kohler engines. Installation is straightforward for anyone comfortable with basic small-engine maintenance and requires only common hand tools.

• Complete fuel pump assembly ready to install—no separate gaskets or diaphragms to source.
• Adapters included where applicable to fit the range of Kohler carburetor connections.
• Simple bolt-on swap; drain or cap remaining fuel and follow safety steps before removal.

Will this repair solve fuel delivery problems and what should I inspect while replacing?

Replacing a worn or leaking pump typically restores steady fuel flow, but also inspect the fuel lines, filter, and carburetor for clogs or damage while you’re working. Replacing the pump gives you a chance to correct related issues that could otherwise limit performance.

• Replace cracked or brittle fuel lines and any clogged inline filters at the same time.
• Check carburetor for varnish or deposits if the engine showed poor running before the pump swap.
• Verify mounting points and gaskets for secure, leak-free sealing after installation.

Who is this for: The DEF Fuel Pump Kit is intended for DIY lawn equipment owners, small-engine repair shops, and fleet maintenance technicians who service Kohler CH- and CV-series engines. It’s ideal when your engine’s existing pump is cracked, leaking, or failing to deliver fuel; technicians will appreciate the direct-replacement fit and included adapters, while homeowners will value a single kit that replaces multiple legacy Kohler part numbers. Always confirm the part number or engine model before ordering to ensure a proper match.