Mikuni Large Round Main Jet #140 4-Pack - Harley & Indian V-Twin
About Mikuni
Mikuni has supplied carburetors and fuel-system components to the motorcycle industry for decades, and its HSR series remains a common choice for carbureted Evolution and Twin Cam V-twins where a clean, tunable fuel curve matters more than electronics.
Optimize your carbureted V-twin's fuel system with this 4-pack of genuine Mikuni Large Round Main Jets in #140 size. These jets are crucial for precise fuel metering through the main circuit, ensuring your Harley-Davidson or Indian Motorcycle engine runs efficiently and powerfully. Essential for changes in altitude, air filters, or exhaust systems.
Why riders pick this
- Genuine Mikuni OEM components for trusted function
- Exact #140 size for precise fuel calibration
- Large round style fits specific Mikuni carburetors
- 4-pack quantity for tuning flexibility or spares
- Crucial for optimizing air/fuel mixture after mods
When you're serious about getting the most out of your carbureted V-twin, precise jetting is key. This 4-pack of #140 Mikuni Large Round Main Jets provides the genuine components you need to fine-tune your fuel mixture. Whether you're addressing a lean condition, compensating for a high-flow air filter, or adjusting after an exhaust upgrade, these jets allow for accurate calibration, ensuring your engine performs at its peak without issues.
Accurate Fuel Metering
- Genuine Mikuni OEM quality for reliable and consistent performance
- #140 orifice size for precise fuel calibration at cruise and mid-range
- Large round body design compatible with specific Mikuni carburetors
- 4-pack quantity for tuning flexibility or keeping spares on hand
The Foundation of a Strong Running V-Twin
A well-tuned carburetor is the heart of a strong running V-twin, and the main jet plays a critical role. With these Mikuni main jets, you can confidently adjust your Harley or Indian motorcycle's fuel delivery to match its unique setup and riding conditions. Having these essential components on hand means you're always ready to optimize your ride for maximum power and efficiency.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FN100604-140
- Quantity: 4 per pack
- Jet Size: #140
- Country of Origin: Japan
Common questions
What does a #140 main jet do?
The #140 main jet controls the volume of fuel supplied to the engine at mid-to-high throttle openings. A larger number like #140 provides a richer fuel mixture, often needed for performance engines or specific modifications.
Will these fit my Harley-Davidson with a Mikuni carburetor?
These jets are designed for V-twin motorcycles that utilize Mikuni carburetors accepting large round main jets. It's important to confirm your specific carburetor model and the jet style it uses to ensure compatibility before ordering.
Do I need a dyno tune after changing main jets?
While you can often get close with careful street tuning, a dyno tune with an experienced technician is the best way to precisely dial in your air/fuel ratio across the entire RPM range for optimal performance and engine health.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | Mikuni |
| TYPE | Jets |
| SKU | 134-7140 |
| WEIGHT | 0.05 lb |
