Mikuni Large Round Main Jets #125 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.
Achieve precise fuel metering for your carbureted V-twin with this 4-pack of Mikuni #125 large round main jets. These genuine Mikuni components are engineered to fine-tune your air-fuel ratio. Essential for riders looking to maximize performance and efficiency on their Harley-Davidson or Indian Motorcycle.
Why riders pick this
- Genuine Mikuni OEM quality for reliable tuning
- Meters fuel at cruise and steady throttle positions
- #125 main jet size for accurate air-fuel ratio
- 4-pack for flexible tuning and backup supply
- Fits V-twin carburetors using large round jets
When you're pushing your Harley-Davidson or Indian Motorcycle, precise fuel delivery is paramount. These Mikuni #125 large round main jets are designed to accurately meter fuel flow at cruise and steady-state throttle positions. This 4-pack provides the essential components for dialing in your carburetor, allowing you to compensate for engine modifications, changes in riding altitude, or different fuel types, ensuring your V-twin runs strong and clean.
Optimized Fuel Management
- Genuine Mikuni OEM jets for trusted reliability
- #125 main jet size for specific fuel calibration
- Large round body style for compatible Mikuni carburetors
- Convenient 4-pack for comprehensive tuning and spares
The Art of Carburetor Tuning
Proper main jet selection is a cornerstone of effective carburetor tuning. It directly impacts your V-twin's performance, throttle response, and fuel economy across the mid-range and top-end RPM band. Always consult your carburetor's tuning guide or a professional mechanic to determine the optimal jetting for your specific engine configuration and riding conditions to achieve the best results.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FN100604-125
- Jet Size: #125
- Quantity: 4 per pack
- Length: 4.4 in
- Width: 2.2 in
- Height: 0.6 in
- Weight: 0.05 lbs
- Country of Origin: Japan
Common questions
What is the function of a #125 main jet in my V-twin's carburetor?
The #125 main jet is crucial for metering the correct amount of fuel at cruise and steady throttle positions. This ensures an optimal air-fuel ratio, which directly impacts your engine's performance, efficiency, and overall health across the mid-range and top-end RPM band.
Will these Mikuni jets fit my Harley-Davidson or Indian Motorcycle?
These large round main jets are designed for V-twin motorcycles equipped with Mikuni carburetors that utilize this style of jet. To ensure proper fitment, please verify your specific carburetor model and its current jet requirements using our Shop by Bike tool before ordering.
Why is purchasing a 4-pack of main jets beneficial for tuning?
A 4-pack provides multiple jets for making incremental adjustments during carburetor tuning, which is often necessary to find the perfect setup. It also ensures you have spare jets on hand for future maintenance or adjustments due to changes in altitude, temperature, or engine modifications.
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 | 134-7125 |
| WEIGHT | 0.05 lb |
