The Honda 91303-ZA1-003 O-Ring is a genuine OEM sealing component listed for a wide range of Honda engines and equipment, including GXV270, GXV340, and GXV390 vertical shaft engines, G300 and G400 horizontal shaft engines, GX360 horizontal shaft engines, EMS4000, EMS4500, ES4500, ES6500, EV4000, and EX5500 generators, the FR700 tiller, and H3011, H3013, H4013, H4514, HT3810, HT3813, and HT4213 riding mowers and lawn tractors. As a direct Honda OEM part, this O-Ring is manufactured to the same specification as the original, ensuring a proper seal without the guesswork of sourcing a generic substitute. Because Honda uses the same part number 91303-ZA1-003 across such a broad range of equipment families, confirm your model and serial number against the fitment table before ordering to be certain this is the correct O-Ring for your specific unit.
Key Features
- Genuine OEM Sealing Integrity — manufactured to Honda's original dimensional specification, so the O-Ring seats correctly and delivers the fluid or air seal the assembly requires
- Broad Cross-Equipment Fitment — listed for Honda vertical shaft engines, horizontal shaft engines, generators, a tiller, and riding mowers and lawn tractors; verify your model and serial number against the fitment table before ordering
- Direct OEM Replacement — carries Honda part number 91303-ZA1-003 exactly as catalogued, making it straightforward to confirm you are ordering the same part that left the factory
- Serial Number Verification Recommended — Honda supersedes O-Ring part numbers at production breaks, so cross-check your machine's serial number against the compatibility table to confirm this is the current correct part for your unit
An O-Ring is a circular elastomeric seal that sits in a machined groove between two mating surfaces or around a shaft or port. When the assembly is torqued together, the O-Ring is compressed slightly, forming a barrier that prevents fluid or air from escaping past the joint. Because the seal depends entirely on the ring maintaining its original cross-sectional diameter and elasticity, a worn, cracked, or incorrectly sized O-Ring will allow leaks that can lead to fluid loss, contamination, or loss of pressure within the system it serves. Replacing a degraded O-Ring with the correct Honda OEM part restores the designed sealing load and prevents the secondary damage that unchecked leaks cause over time.
Part Details
| Part Number | 91303-ZA1-003 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | O-Ring |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | EMS4000, EMS4500 | 1061324-9999999 |
| Generator | ES4500, EV4000 | 1294568-9999999 |
| Generator | ES6500, EX5500 | All |
| Horizontal Shaft Engine | G300 | 1232729-1449966 |
| Horizontal Shaft Engine | G400 | 1294568-1516911 |
| Horizontal Shaft Engine | GX360 | All |
| Lawn Tractor | H4013 | 1000001-2015425 |
| Lawn Tractor | HT3810 | 1388993-9999999 |
| Lawn Tractor | H4514, HT3813, HT4213 | All |
| Riding Mower | H3011, H3013 | 1000001-2020474 |
| Tiller | FR700 | All |
| Vertical Shaft Engine | GXV390 | 1000001-2008435 |
| Vertical Shaft Engine | GXV270, GXV340 | 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.
