Mikuni Large Round Main Jets #90 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 Large Round Main Jets in #90 size. These genuine Mikuni components are crucial for fine-tuning your carburetor after installing different air filters, exhausts, or adjusting for elevation changes.
Why riders pick this
- Genuine Mikuni OEM quality for consistent results
- Accurate #90 main jet for controlled fuel delivery
- Large round design for proper fitment
- Convenient 4-pack for flexible tuning options
- Essential for dialing in carburetors on V-twin motorcycles
When you're pushing the limits of your Harley-Davidson or Indian Motorcycle, proper carburetor tuning is non-negotiable. This 4-pack of Mikuni Large Round Main Jets, sized #90, gives you the control needed to dial in your V-twin's fuel delivery, ensuring optimal performance and a crisp throttle response across the main circuit.
Enhanced Fuel System Control
- Genuine Mikuni OEM parts for reliable and consistent performance
- #90 main jet size for precise fuel flow adjustments at cruise and part-throttle
- Large round body style ensures correct fitment in compatible Mikuni carburetors
- Supplied in a 4-pack, providing flexibility for iterative tuning sessions
Critical for Performance Upgrades
Any modification to your V-twin's intake or exhaust system, or even a change in riding altitude, can necessitate a main jet adjustment. Using these #90 jets allows you to richen the fuel mixture as needed, preventing lean conditions and optimizing power output. This pack ensures you have the necessary components to achieve a balanced and powerful tune for your motorcycle.
Specifications
- Brand: Mikuni
- Manufacturer Part #: FN100604-90
- Jet Size: #90
- 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 role of a #90 main jet?
The #90 main jet controls the fuel flow through the main circuit of your carburetor, primarily affecting the air-fuel mixture at cruise and part-throttle RPMs. Upsizing typically richens the mixture, while downsizing leans it out.
Why would I need to rejet my V-twin's carburetor?
Rejetting is often necessary after installing performance air filters, upgrading exhaust systems, making engine modifications, or riding at significantly different altitudes to maintain an optimal air-fuel ratio and ensure smooth running.
How many jets are included in this pack?
This product includes four Mikuni Large Round Main Jets in the #90 size. This provides spares or options for fine-tuning your carburetor.
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 | 134-7090 |
| WEIGHT | 0.05 lb |
