Mikuni Jet Needle HSR45 Leaner Taper - 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 for HSR45 carburetors features a leaner taper specification. It's engineered to reduce fuel flow and lean out the air-fuel mixture across the throttle range, particularly useful for correcting over-rich conditions. This direct replacement part is essential for riders fine-tuning carburetor performance on V-twin engines.
Why riders pick this
- Leaner taper for reduced fuel flow
- Direct replacement for HSR45 Mikuni carbs
- Helps correct over-rich conditions
- Optimizes air-fuel mixture across throttle
- Essential for precision carb tuning
When your V-twin running an HSR45 Mikuni carburetor is experiencing an overly rich condition, especially at higher RPMs or specific throttle positions, a leaner jet needle can be the solution. This needle's specific taper is designed to reduce fuel flow, thereby leaning out the air-fuel mixture. This adjustment is crucial for optimizing combustion, preventing fouled plugs, and improving overall engine efficiency. It's a key component for precision tuning and achieving the correct air-fuel ratio for your specific engine setup.
Correct Over-Rich Conditions
- Leaner taper specification reduces fuel flow
- Direct replacement for Mikuni HSR45 carburetors
- Helps lean out the air-fuel mixture across the throttle range
- Essential for preventing fouled plugs and optimizing combustion
Precision Tuning for Your HSR45
Achieving the perfect air-fuel mixture is vital for maximizing both performance and longevity of your V-twin engine. If your HSR45-equipped Harley or Indian motorcycle is running too rich, this leaner taper jet needle offers a targeted adjustment to bring the mixture back into optimal range. It works in conjunction with other jetting components to create a balanced fuel curve, ensuring crisp throttle response and clean burning across all RPMs.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FJ8-8CFY02-98
- Length: 4.4 in
- Weight: 0.05 lbs
- Country of Origin: Japan
Common questions
What does a leaner jet needle do?
A leaner taper reduces fuel flow as the throttle opens, leaning out the air-fuel ratio. This is particularly useful for correcting over-rich conditions, preventing fouled plugs, and optimizing higher RPM operation.
Will this jet needle fit my Mikuni HSR45 carburetor?
Yes, this needle is a direct replacement for HSR45 Mikuni carburetors. Please verify your specific carb model and current jetting needs before ordering.
Do I need any other carburetor tuning parts?
Jet needles work alongside main jets and pilot jets to control the entire fuel curve. For comprehensive tuning, you may consider adjusting these other components to achieve your desired air-fuel ratio.
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 | 14-2503 |
| WEIGHT | 0.05 lb |
