The Honda 18310-ZJ1-801 Left Side Muffler Complete is a genuine OEM exhaust component designed for GX610 and GX620 horizontal shaft engines. As a direct OEM replacement, this muffler is built to Honda's original specifications, ensuring proper exhaust flow and fit on these large-displacement twin-cylinder engines. Confirm your engine's serial number against the fitment table before ordering, as Honda supersedes parts at specific serial breaks. Part number 18310-ZJ1-801 is the correct left-side unit — verify your engine's configuration to ensure you are ordering the appropriate side.
Key Features
- Genuine OEM Exhaust Integrity — sourced directly from Honda, this muffler matches the original exhaust backpressure and port geometry of the GX610 and GX620 engines, preserving power output and combustion efficiency.
- Left-Side Specific Fitment — the GX610 and GX620 are twin-cylinder engines with separate left and right exhaust outlets; this is the left-side unit, so verify your engine's layout before purchasing.
- Serial Number Verification Recommended — Honda updates exhaust components at serial break points; check your engine's serial number against the compatibility table to confirm part number 18310-ZJ1-801 is correct for your unit.
- Restored Exhaust Performance — a cracked or failed muffler causes excessive noise, loss of back pressure, and potential heat exposure to surrounding components; replacing it restores proper exhaust management and quieter operation.
The muffler on a horizontal shaft engine is responsible for directing hot exhaust gases away from the engine, reducing combustion noise, and controlling exhaust backpressure — all of which affect how smoothly and efficiently the engine runs. On the twin-cylinder GX610 and GX620, each cylinder bank has its own dedicated muffler; the left-side unit handles exhaust from one bank independently. When a muffler cracks, corrodes, or loses its seal, exhaust noise increases sharply, surrounding components are exposed to uncontrolled heat, and engine performance can degrade — making timely replacement with the correct OEM part essential.
Part Details
| Part Number | 18310-ZJ1-801 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Left Side Muffler Complete |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX610, GX620 | 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.
