The Honda 14721-ZE5-000 Exhaust Valve is a genuine OEM Exhaust Valve designed for HRM21 and HRS21 lawn mowers. As a direct Honda OEM component, this valve is manufactured to the same specification as the original, ensuring a proper seat, correct stem dimensions, and reliable sealing in the cylinder head. Confirm your mower's serial number against the fitment table before ordering, as Honda supersedes components at serial breaks and the correct valve depends on your specific build.
Key Features
- Genuine Honda OEM Valve — manufactured to Honda's original specification for accurate seating geometry and stem-to-guide clearance, both critical to combustion sealing in a lawn mower engine
- Exact Cylinder Head Fit — this exhaust valve is engineered to match the original port dimensions and seat angle in the HRM21 and HRS21 cylinder head, keeping installation straightforward
- Confirmed Fitment — sourced specifically for HRM21 and HRS21 lawn mowers; verify your serial number against the compatibility table to ensure this is the correct valve for your unit
- Combustion Integrity — a properly seating exhaust valve holds compression and allows spent gases to exit cleanly; a worn or burnt valve causes hard starting, lost power, and excessive oil consumption
The exhaust valve sits in the cylinder head and opens on the exhaust stroke to allow combustion gases to exit the engine before the next intake cycle begins. It must seal completely when closed so the engine builds adequate compression — without a tight seal, power drops noticeably and the engine becomes difficult to start. Over time, heat cycling and carbon buildup cause the valve face and seat to wear or pit, eventually preventing a full seal and making valve replacement necessary to restore normal engine performance.
Part Details
| Part Number | 14721-ZE5-000 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Exhaust Valve |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Lawn Mower | HRM21, HRS21 | 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.
