The Honda 35120-Z0T-821 is a genuine OEM Engine Stop Switch Assembly (Toyo Denso) designed for a wide range of Honda horizontal shaft engines and water pumps, including the GX120, GX160, GX200, GX25, GX35, and GXH50 engines, as well as the WH15, WH20, and WX10 water pumps. Sourced directly from Honda, this assembly matches the original switch unit precisely, ensuring proper electrical contact and reliable shutdown behavior every time the operator needs to cut power. If the existing switch is worn, corroded, or no longer grounding correctly, this replacement restores the engine's ability to stop on demand — a critical function for day-to-day operation and servicing.
Key Features
- Genuine Honda OEM Electrical Contact — manufactured to Honda's original specifications by Toyo Denso, ensuring the switch grounds the ignition circuit cleanly and consistently, with no intermittent behavior or false triggering
- Broad Horizontal Shaft Coverage — fits GX120, GX160, GX200, GX25, GX35, and GXH50 horizontal shaft engines, as well as WH15, WH20, and WX10 water pumps, making it a versatile replacement across Honda's lineup
- Direct Drop-In Replacement — this switch assembly is built to match the original connector, mounting points, and actuator geometry, so installation follows the factory service procedure without modification
- Check Your Serial Number — Honda supersedes switch assemblies at production breaks; verify your engine or pump serial number against the fitment table before ordering to confirm this is the correct variant for your unit
The engine stop switch is the primary operator control for shutting down the engine. When pressed or toggled, it grounds the ignition system, interrupting the spark signal and bringing the engine to a controlled stop. On water pumps such as the WH15, WH20, and WX10, this function is equally important — it gives the operator an immediate way to halt the pump motor safely. A switch that fails to ground reliably will leave the engine running when it should stop, while one with a broken or intermittent contact may cause nuisance shutdowns during operation. Replacing a faulty switch with the correct OEM assembly restores predictable, single-action shutdown performance and ensures the machine responds exactly as intended when the operator cuts power.
Part Details
| Part Number | 35120-Z0T-821 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Engine Stop Switch Assembly (Toyo Denso) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GXH50 | 1027540-9999999 |
| Horizontal Shaft Engine | GX35 | 1307449-9999999 |
| Horizontal Shaft Engine | GX25 | 1333507-9999999 |
| Horizontal Shaft Engine | GX120, GX160, GX200 | All |
| Water Pump | WX10 | 2933625-9999999 |
| 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.
