The Honda 28451-Z4H-003 Starter Pulley is a genuine OEM Starter Pulley designed for GX120 horizontal shaft engines and WB20, WB30, WH15, and WH20 water pumps. As a direct Honda OEM component, this pulley is manufactured to the same specification as the original, ensuring it seats and engages correctly within the recoil starter assembly. Confirm your unit's serial number against the fitment table before ordering, as Honda supersedes parts at specific serial breaks across this range.
Key Features
- Genuine Honda OEM Part — sourced directly from Honda, this Starter Pulley matches the original rope-winding geometry and pawl interface, so the recoil starter operates with the correct tension and engagement from the first pull.
- Broad Fitment Across Engines and Water Pumps — fits the GX120 horizontal shaft engine as well as WB20, WB30, WH15, and WH20 water pumps; check part number 28451-Z4H-003 against your machine's serial number to confirm the right application.
- Recoil Function Restored — a worn or cracked pulley causes the starter rope to slip, fray, or fail to retract; replacing it with this OEM component restores smooth rope winding and reliable starter action.
- Serial-Number Verification Recommended — Honda updates part supersessions at defined serial breaks, so always cross-reference your machine's serial number with the compatibility table to ensure this is the correct pulley for your unit.
The starter pulley is the rope-winding spool at the heart of the recoil starter. When you pull the starter handle, the rope unwinds from the pulley, spinning it and engaging the pawls that turn the engine or pump over for starting. A return spring then rewinds the rope onto the pulley as the handle is released. When the pulley cracks, wears, or the rope groove becomes damaged, the rope can slip or jam and the starter will no longer crank the engine reliably. Replacing a damaged pulley with a correct OEM part restores the full starting cycle and prevents further damage to the surrounding recoil starter components.
Part Details
| Part Number | 28451-Z4H-003 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Starter Pulley |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX120 | 1154037-9999999 |
| Water Pump | WB20, WB30, WH15, WH20 | 1422407-9999999 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
