The Honda 18310-ZE2-U91 Muffler (Denyo) is a genuine OEM exhaust component designed for GX240, GX340, and GX390 horizontal shaft engines. As a direct Honda OEM replacement, this muffler is manufactured to the same standards as the original unit, ensuring a correct fit without guesswork or modification. Confirm your engine's serial number against the fitment table before ordering, as Honda supersedes parts at serial breaks and this muffler is specific to select production runs.
Key Features
- Genuine Honda OEM Part — sourced directly from Honda, this muffler meets the same exhaust flow and backpressure specifications as the original, maintaining engine performance and sound levels over time
- Denyo Variant Fit — the Denyo designation identifies a specific muffler configuration; confirm this variant matches your engine's application before purchasing, particularly if more than one muffler option is listed for your model
- Fits GX240, GX340, and GX390 Horizontal Shaft Engines — compatible across three displacement classes in Honda's commercial horizontal shaft engine lineup; reference your model code to confirm
- Serial Number Verification Recommended — Honda introduces part supersessions at defined serial breaks; check your engine's serial number against the fitment table to confirm this is the correct muffler for your specific unit
- Exhaust Integrity — a worn or damaged muffler allows uncontrolled exhaust escape, increases noise output, and can affect engine back pressure, which in turn reduces power and fuel efficiency
The muffler is the final stage of an engine's exhaust system. Hot combustion gases exit the cylinder head through the exhaust port and pass through the muffler, which dampens sound by routing gases through internal chambers before they vent to atmosphere. A functioning muffler keeps exhaust noise within an acceptable range and maintains the correct back pressure the engine is tuned to operate against. When a muffler cracks, corrodes, or develops a leak, exhaust escapes before it is properly silenced — noise increases sharply, and the loss of back pressure can reduce power output and increase fuel consumption. Replacing a failed muffler with a correct Honda OEM unit, part number 18310-ZE2-U91, restores proper exhaust flow and keeps the engine running as intended.
Part Details
| Part Number | 18310-ZE2-U91 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Muffler (Denyo) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX340 | 1000001-1178772, 2374606-9999999 |
| Horizontal Shaft Engine | GX240, GX390 | 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.
