Mikuni Large Round Main Jets #142.5 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.
Unlock the full potential of your V-twin with these Mikuni large round main jets in size #142.5. This 4-pack provides the precision components needed for accurate carburetor tuning. Trusted by Harley-Davidson and Indian Motorcycle riders, these genuine Mikuni jets ensure optimal fuel metering for enhanced performance.
Why riders pick this
- Genuine Mikuni OEM quality for reliable performance
- Specific #142.5 jet size for precise tuning
- Large round main jet design for Mikuni carburetors
- Includes four jets for versatile tuning and spare parts
For riders pushing their Harley-Davidson or Indian Motorcycle beyond stock limits, precise fuel control is paramount. These Mikuni large round main jets in #142.5 are engineered to deliver consistent fuel flow, allowing you to fine-tune your V-twin's carburetor for maximum efficiency and power. Whether you're compensating for elevation changes or new engine modifications, correct jetting is key.
Enhanced Fuel Control
- Genuine Mikuni OEM parts for assured quality and fitment
- Specific #142.5 size for targeted fuel delivery adjustments
- Large round design for compatibility with many Mikuni carbs
- Convenient 4-pack for comprehensive tuning options and spares
Performance Tuning Essentials
Effective carburetor tuning significantly impacts your V-twin's throttle response and overall performance. These main jets play a crucial role in metering fuel during mid-to-full throttle operation, making them indispensable for riders seeking to optimize their bike's engine characteristics. Ensure your Harley or Indian Motorcycle runs strong and clean with the right Mikuni jetting.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FN100604-142.5
- Jet Size: #142.5
- Quantity: 4 per pack
- Country of Origin: Japan
Common questions
What is the purpose of a main jet in a V-twin carburetor?
The main jet meters the amount of fuel delivered at cruising speeds and higher throttle openings, ensuring the engine receives the correct air-fuel mixture for optimal power and efficiency.
How does this #142.5 jet size compare to other Mikuni jets?
A #142.5 jet provides a specific fuel flow rate. Generally, a larger number indicates a richer fuel mixture, while a smaller number results in a leaner mixture. This size is part of a range used for fine-tuning.
Are these jets compatible with all Harley-Davidson and Indian Motorcycle carburetors?
These are genuine Mikuni large round main jets and will only fit V-twin motorcycles equipped with Mikuni brand carburetors. They are not compatible with stock Keihin, S&S, or other carburetor brands unless a Mikuni carb has been installed.
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 | 134-71425 |
| WEIGHT | 0.05 lb |
