Mikuni Jet Needle HSR45 Richer Calibration - 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.
This Mikuni jet needle is specifically designed for HSR45 carburetors, featuring a richer calibration taper. It precisely adjusts fuel delivery in the mid-range throttle position, allowing for finer tuning of your V-twin's performance. This genuine Mikuni OEM replacement part is ideal for optimizing HSR45-equipped engines.
Why riders pick this
- Richer calibration for HSR45 carburetors
- Adjusts midrange fuel delivery
- Direct Mikuni OEM replacement part
- Improves throttle response and power
- Ideal for fine-tuning V-twin engines
Dialing in the fuel mixture on your V-twin's HSR45 Mikuni carburetor is crucial for smooth throttle response and optimal power. This jet needle, with its richer calibration, delivers more fuel in the mid-range throttle position compared to a standard needle. This adjustment can significantly improve transitions between cruise and acceleration, helping to eliminate flat spots and ensure your engine runs efficiently. It's a key component for riders looking to fine-tune their carbureted setup.
Smooth Out Mid-Range Performance
- Richer calibration for enhanced mid-range fuel delivery
- Direct Mikuni OEM replacement for HSR45 carburetors
- Improves throttle response and eliminates lean conditions
- Essential component for precise carburetor tuning
Optimize Your HSR45 Fuel Curve
Achieving the ideal air-fuel ratio across the entire RPM range is the goal of any carb tuner. This richer jet needle for the HSR45 Mikuni carburetor provides a targeted adjustment to the mid-range, often necessary when compensating for intake or exhaust upgrades, or to simply achieve a smoother, more powerful delivery. Combine it with other Mikuni jetting components to build a custom fuel curve that unleashes the full potential of your Harley or Indian V-twin.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FJ8-8CFY02-96
- Length: 4.4 in
- Width: 1.9 in
- Height: 0.4 in
- Weight: 0.05 lbs
- Country of Origin: Japan
Common questions
What does a richer jet needle do?
A richer needle delivers more fuel in the midrange throttle position, which can improve throttle response, smooth transitions between cruise and acceleration, and prevent lean conditions.
Will this jet needle fit my Mikuni HSR45 carburetor?
Yes, this is a direct Mikuni OEM replacement jet needle for HSR45 carburetors. Always confirm your specific carb model before ordering to ensure compatibility.
Do I need to change other carburetor parts when swapping needles?
Changing just the jet needle primarily adjusts midrange fuel delivery. For complete tuning, you may also consider adjusting main jets and pilot jets, depending on your engine's overall setup and desired performance.
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 | Intake/Carb/Fuel System |
| SKU | 14-2501 |
| WEIGHT | 0.05 lb |
