The Honda 12000-Z0S-405 Cylinder Assembly is a genuine OEM Cylinder Assembly designed for GX120 horizontal shaft engines, WH15 water pumps, and WH20 water pumps. As a direct Honda OEM component, this assembly is manufactured to the same specification as the original part it replaces, ensuring a correct fit with no guesswork. Confirm your machine's serial number against the fitment table before ordering, as Honda issues part supersessions at specific serial breaks within the same model line.
Key Features
- Genuine Honda OEM Construction — sourced directly from Honda, this Cylinder Assembly matches the original bore dimensions and porting geometry required for correct compression and power delivery
- Direct OEM Replacement — engineered to drop in as a like-for-like replacement, preserving the integrity of the engine's core structure without rework or adaptation
- Broad Confirmed Fitment — designed for GX120 horizontal shaft engines, WH15 water pumps, and WH20 water pumps, including multiple serial ranges within each model
- Check Your Serial Number — Honda supersedes cylinder components at specific production breaks; verify your unit's serial number against the compatibility table to confirm part number 12000-Z0S-405 is correct for your machine
- Core Engine Integrity — a sound cylinder is the foundation of combustion efficiency; a cracked, scored, or worn cylinder leads to compression loss, excessive oil consumption, and ultimately engine failure
The cylinder assembly is the structural and functional core of the engine. It houses the piston and forms the combustion chamber where the air-fuel mixture ignites to generate power. The cylinder bore must maintain precise dimensions to allow the piston and rings to seal effectively — when the bore becomes worn or scored, compression drops, oil passes into the combustion chamber, and the engine loses both power and efficiency. On water pumps such as the WH15 and WH20, a healthy engine cylinder is what sustains the shaft power needed to drive the pump impeller at its rated output. Replacing a damaged cylinder assembly with a genuine Honda OEM unit restores the engine to its original operating condition.
Part Details
| Part Number | 12000-Z0S-405 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Cylinder Assembly |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX120 | All |
| Water Pump | WH15, WH20 | All |
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.
