The Honda 12391-ZJ1-000 Head Cover Gasket is a genuine OEM replacement designed for GX610 and GX620 horizontal shaft engines, GXV610 and GXV620 vertical shaft engines, the EB11000 generator, HA4118 and HA4120 lawn tractors, and HRC7018 and HRC7020 commercial mowers. As a direct OEM part, this gasket is manufactured to Honda's exact specifications, ensuring a proper seal every time. Confirm your machine's serial number against the fitment table before ordering, as Honda updates parts at serial breaks and the correct gasket matters for a leak-free result.
Key Features
- OEM Sealing Integrity — genuine Honda construction ensures the gasket conforms precisely to the mating surfaces of the head cover, preventing oil leaks and maintaining crankcase pressure balance
- Direct OEM Replacement — part number 12391-ZJ1-000 installs in place of the original with no rework to the head cover or cylinder head
- Broad Fitment — covers GX610 and GX620 horizontal shaft engines, GXV610 and GXV620 vertical shaft engines, the EB11000 generator, HA4118 and HA4120 lawn tractors, and HRC7018 and HRC7020 commercial mowers
- Serial Number Verification Recommended — Honda supersedes gaskets at production breaks; check your unit's serial number against the fitment table to confirm this is the right version for your machine
- Leak Prevention — a compromised or hardened head cover gasket allows oil to seep past the cover, leading to external contamination and potential oil loss; replacing it restores a clean, dry seal
The head cover gasket seats between the valve cover and the cylinder head, forming a static oil seal that keeps engine oil contained within the valve train area. It must maintain a consistent compression under the cover's clamping load across a wide range of operating temperatures. When the gasket hardens, shrinks, or cracks with age, oil works its way past the sealing surface and onto the exterior of the engine — a condition that worsens over time and can mask more serious oil consumption issues if left unchecked.
Part Details
| Part Number | 12391-ZJ1-000 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Head Cover Gasket |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Commercial Mower | HRC7018, HRC7020 | All |
| Generator | EB11000 | All |
| Horizontal Shaft Engine | GX610, GX620 | All |
| Lawn Tractor | HA4118, HA4120 | All |
| Vertical Shaft Engine | GXV610, GXV620 | 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.
