The Honda 99131-Z0A-0850 Main Jet (#85) is a genuine OEM component designed for GCV520, GCV530, GXV520, and GXV530 vertical shaft engines. Sourced directly from Honda, this jet is the exact calibrated orifice these engines require for correct fuel metering at full throttle. Whether you are rebuilding a carburetor or diagnosing a rich or lean condition, installing the correct Honda main jet restores the fuel delivery your engine was engineered to run on.
Key Features
- Correct Jet Sizing — the #85 orifice diameter is Honda's specified calibration for these engines; an incorrect size will produce a rich or lean mixture, robbing power and affecting emissions
- Genuine OEM Component — supplied by Honda, this main jet matches the original carburetor specification exactly, so no adjustment or retuning is needed after installation
- Broad Vertical-Engine Fitment — listed for GCV520, GCV530, GXV520, and GXV530 vertical shaft engines, including both residential GCV and commercial GXV variants in this displacement class
- Serial-Range Awareness — Honda supersedes carburetor jets at serial breaks, so confirm your engine's serial number against the fitment table before ordering
The main jet is the precision metering orifice inside the carburetor that controls how much fuel enters the airstream at wide-open throttle. Its calibrated bore size determines the air-to-fuel ratio the engine runs on under load — too small and the engine runs lean and overheats; too large and it runs rich, fouling the spark plug and burning excess fuel. When a main jet becomes blocked with varnish deposits or is damaged during a carburetor cleaning, replacing it with the correct Honda-specified jet is essential to restoring full power and clean combustion on GCV520, GCV530, GXV520, and GXV530 engines.
Part Details
| Part Number | 99131-Z0A-0850 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Main Jet (#85) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Vertical Shaft Engine | GCV520, GCV530, GXV520, GXV530 | 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.
