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Start ShoppingMIKUNI F4/042-250 Hex Main Jets - Precision Fuel Jetting for High-Performance Engines
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Description
Upgrade your engine's fuel delivery system with MIKUNI's F4/042-250 Hex Main Jets. These precision-machined components ensure optimal air-fuel mixture for enhanced power, responsiveness, and fuel efficiency in high-performance engines.
Key Features
- Hexagonal Design: Ensures secure, leak-free installation in MIKUNI carburetor systems for reliable fuel flow.
- Precision Machining: Factory-tuned jetting for accurate fuel metering across a wide range of engine speeds and loads.
- Durable Construction: High-grade brass alloy resists corrosion and maintains performance in harsh riding conditions.
- Easy Installation: Standardized sizing simplifies replacement and tuning for DIY mechanics and professionals.
Why Choose This Product
MIKUNI's F4/042-250 jets deliver consistent performance for racing, off-road, and street use. Their precise calibration reduces fuel waste while maximizing horsepower and throttle response. The robust construction ensures long-term reliability, making them a trusted choice for riders demanding peak engine performance.
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Upgrade your engine's fuel delivery system with MIKUNI's F4/042-250 Hex Main Jets. These precision-machined components ensure optimal air-fuel mixture for enhanced power, responsiveness, and fuel efficiency in high-performance engines.
Key Features
- Hexagonal Design: Ensures secure, leak-free installation in MIKUNI carburetor systems for reliable fuel flow.
- Precision Machining: Factory-tuned jetting for accurate fuel metering across a wide range of engine speeds and loads.
- Durable Construction: High-grade brass alloy resists corrosion and maintains performance in harsh riding conditions.
- Easy Installation: Standardized sizing simplifies replacement and tuning for DIY mechanics and professionals.
Why Choose This Product
MIKUNI's F4/042-250 jets deliver consistent performance for racing, off-road, and street use. Their precise calibration reduces fuel waste while maximizing horsepower and throttle response. The robust construction ensures long-term reliability, making them a trusted choice for riders demanding peak engine performance.| SKU | GM83A88251 |
|---|---|
| MPN | F4/042-250 |
| Brand | MIKUNI |
| Category | Jets |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Suzuki | RM250 | 1985-2005 |
| Honda | CR250R | 1990-2010 |
| Kawasaki | KX250 | 1986-2008 |
| Yamaha | YZ250 | 1995-2020 |
| KTM | 250 SX | 2000-2015 |
Frequently Asked Questions
Fits Mikuni TM, VM, and BS series carburetors commonly found on 2-stroke dirt bikes and some 4-strokes.
Use a jet kit or dyno tune; 250 is typical for stock mid-range setups at sea level.
Hex head (F4 series) allows tool installation without marring; interchangeable with round jets of same size.
No, this is for carbureted engines only.
Installation Guide
Difficulty
Easy
Est. Time
5 min
Tools Required
- Small flathead screwdriver
- Needle nose pliers
Pro Tips
- Count turns on old jet to match on new one
- Use carb cleaner on threads for smooth install
Common Mistakes to Avoid
- Installing without removing old jet fully
- Not cleaning carb bowl before install
Comparison vs Stock/OEM
Direct replacement for OEM main jets; precision machined brass for consistent flow
Improvements
- Better fuel metering accuracy
- Easier installation with hex head
- Corrosion resistant
Considerations
- Aftermarket tuning required for optimal performance
Durability & Warranty
Expected Lifespan
Indefinite with proper carb maintenance
Warranty
Limited lifetime from Mikuni
Maintenance
Inspect during carb cleans; replace if clogged
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