The Honda 99101-124-0900 Main Jet (#90) is a genuine OEM carburetor component designed for a wide range of Honda engines and power equipment, including GX240 and GX340 horizontal shaft engines, E3500, EB4000, EM4000, EMS4000, EMS4500, ES3500, ES6500, and EX5500 generators, the FR700 tiller, G400 horizontal shaft engines, HS80 two-stage snow blowers, and HT3813 and HT4213 lawn tractors. As a genuine Honda part, it carries the exact #90 sizing calibrated to the fuel delivery requirements Honda specifies for each of these units. This Main Jet (#90) is a direct OEM replacement that slots into the carburetor float bowl without modification, restoring correct fuel flow to the engine or equipment. Because Honda supersedes jet sizes at production breaks, confirm your unit's serial number against the fitment table before ordering.
Key Features
- Exact OEM Jetting — the #90 sizing is Honda's factory-specified orifice diameter, ensuring the carburetor meters the correct fuel volume for clean combustion across load ranges
- Broad Genuine OEM Coverage — listed for GX240 and GX340 engines, multiple Honda generator models, the FR700 tiller, G400 engines, HS80 snow blowers, and HT3813 and HT4213 lawn tractors — genuine Honda part number 99101-124-0900
- Direct Drop-In Replacement — threads directly into the carburetor bowl in the same position as the original, with no reaming, drilling, or adaptation needed
- Serial Number Verification Recommended — Honda updates carburetor jetting at production serial breaks; check your machine's serial number against the fitment table to confirm this is the correct jet for your unit
- Restores Fuel Metering Performance — a worn, clogged, or incorrectly sized main jet causes rich or lean running, hard starting, and loss of power under load; replacing it with the correct OEM jet brings fuel delivery back to spec
The main jet is the precision orifice inside the carburetor that controls how much fuel enters the air stream at mid to full throttle. Its calibrated hole size — in this case #90 — determines the air-fuel ratio the engine runs on under load, and even a partially blocked or incorrectly sized jet will cause the engine to run rough, lose power, surge, or fail to reach full speed. Replacing a damaged or clogged main jet with the correct genuine OEM component restores the carburetor's fuel metering to specification, bringing the engine or equipment back to its intended operating condition.
Part Details
| Part Number | 99101-124-0900 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Main Jet (#90) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Generator | E3500, EB4000, EM4000, EMS4000, EMS4500, ES3500, ES6500, EX5500 | All |
| Horizontal Shaft Engine | G400, GX240, GX340 | All |
| Lawn Tractor | HT3813, HT4213 | All |
| Tiller | FR700 | All |
| Two-Stage Snow Blower | HS80 | 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.
