The Honda 18321-ZJ1-010 Muffler Protector (High) is a genuine OEM heat shield designed for GX610, GX620, GX630, GX660, GX670, and GX690 horizontal shaft engines. As a direct OEM replacement, this protector is manufactured to the same specification as the part that left the factory, ensuring it seats and fastens correctly without alteration. If your existing protector is cracked, warped, or missing, this is the correct service replacement for the full range of GX600- and GX670-series big-block horizontal shaft engines listed above. Always cross-reference the serial number on your engine against the fitment table to confirm this is the right part number 18321-ZJ1-010 for your specific unit, as Honda does revise parts at serial breaks.
Key Features
- Genuine OEM Heat Protection — sourced directly from Honda, this protector delivers the same thermal shielding performance as the original, guarding against burns and heat damage in the demanding operating environments these large-displacement engines produce.
- Direct OEM Replacement — engineered to the exact profile of the original, this part installs without modification on GX610, GX620, GX630, GX660, GX670, and GX690 horizontal shaft engines.
- Broad GX Big-Block Fitment — covers Honda's full lineup of large horizontal shaft engines from the GX610 through the GX690, making it the correct service part for a wide range of commercial-grade equipment.
- Serial Number Verification Recommended — Honda supersedes protective components at production breaks, so confirm your engine's serial number against the fitment table before ordering.
The Muffler Protector (High) is a heat shield that surrounds the muffler on Honda's large-displacement horizontal shaft engines, forming a barrier between the hot exhaust system and surrounding components, nearby materials, and anyone working close to the machine. On high-output engines like the GX610 through GX690 series, the muffler reaches temperatures that can ignite debris or cause contact burns in a matter of seconds. When the protector is cracked, broken away, or missing entirely, the muffler surface is left exposed, creating a genuine burn hazard and increasing the risk of heat damage to adjacent wiring, hoses, and bodywork on the equipment it powers.
Part Details
| Part Number | 18321-ZJ1-010 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Muffler Protector (High) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX670 | 1065383-9999999 |
| Horizontal Shaft Engine | GX610, GX620, GX630, GX660, GX690 | 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.
