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Start ShoppingMIKUNI F4/042-100 Hex Main Jets - Precision Fuel Control for High-Performance Engines
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Description
Upgrade your MIKUNI carburetor with precision-engineered hex main jets designed to deliver consistent fuel-air mixture ratios for maximum power and efficiency. These critical components ensure smooth engine operation across a wide range of RPMs and environmental conditions.
Key Features
- Hexagonal Design: Secure fitment for precise fuel metering in high-performance engines
- High-Durability Alloy: Resists corrosion and wear for long-lasting performance
- Model-Specific Compatibility: Engineered for MIKUNI F4/042-100 carburetor systems
- Easy Installation: Simple replacement for quick maintenance and tuning
- Adjustable Flow Rates: Fine-tune fuel delivery for optimal engine response
Why Choose This Product
These main jets are essential for riders seeking peak engine performance and reliability. Their precise fuel metering capabilities improve throttle response, enhance fuel efficiency, and reduce emissions. The durable construction ensures consistent performance through demanding conditions, while the hex design provides a secure fit to prevent fuel delivery issues. Whether you're modifying a sport bike or tuning a competition engine, these jets offer the accuracy needed for professional-level results.
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Upgrade your MIKUNI carburetor with precision-engineered hex main jets designed to deliver consistent fuel-air mixture ratios for maximum power and efficiency. These critical components ensure smooth engine operation across a wide range of RPMs and environmental conditions.
Key Features
- Hexagonal Design: Secure fitment for precise fuel metering in high-performance engines
- High-Durability Alloy: Resists corrosion and wear for long-lasting performance
- Model-Specific Compatibility: Engineered for MIKUNI F4/042-100 carburetor systems
- Easy Installation: Simple replacement for quick maintenance and tuning
- Adjustable Flow Rates: Fine-tune fuel delivery for optimal engine response
Why Choose This Product
These main jets are essential for riders seeking peak engine performance and reliability. Their precise fuel metering capabilities improve throttle response, enhance fuel efficiency, and reduce emissions. The durable construction ensures consistent performance through demanding conditions, while the hex design provides a secure fit to prevent fuel delivery issues. Whether you're modifying a sport bike or tuning a competition engine, these jets offer the accuracy needed for professional-level results.| SKU | GM5D567BC2 |
|---|---|
| MPN | F4/042-100 |
| Brand | MIKUNI |
| Category | Jets |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Various Japanese | Keihin/Mikuni carbureted bikes | 1985-2024 |
| Honda | XR series (XR250R, XR400R, XR650R) | 1990-2005 |
| Suzuki | DR350, DRZ400 | 1986-2003 |
| Yamaha | XT350, TTR225 | 1990-2010 |
| Kawasaki | KLX series, KDX | 1980-2024 |
Frequently Asked Questions
The main jet controls fuel flow at mid-range to full throttle operation. It's critical for proper engine performance, fuel economy, and preventing lean-running conditions that can damage the engine.
Jet size depends on your engine displacement, altitude, air temperature, and modifications. Consult your carburetor manual, manufacturer recommendations, or tuning guides. Common sizes range from #60 to #180.
It's best to use Mikuni jets in Mikuni carburetors. While some aftermarket jets may fit, Mikuni jets are engineered for optimal performance and reliability in Mikuni carburetors.
Main jets don't wear out like consumables. They last indefinitely unless damaged. Replace only if clogged, damaged, or when changing jetting for performance tuning.
Hex jets have a hexagonal head for easier removal/installation with a wrench or socket. Non-hex jets typically require a jet removal tool. Hex design is more convenient for tuning.
Installation Guide
Difficulty
Easy
Est. Time
15 min
Tools Required
- Hex wrench or socket (size depends on jet)
- Carburetor removal tools (if full carb service)
- Gasket scraper
- Clean rags
Pro Tips
- Keep jets organized by size when removing multiple jets
- Clean jet passages with carburetor cleaner
- Use a light touch when seating the jet - snug but not tight
- Document original jet size before changes
- Test ride after jetting changes to verify performance
Common Mistakes to Avoid
- Over-tightening the jet (can strip threads)
- Not cleaning the jet cavity before installation
- Installing wrong jet size for your application
- Not replacing gaskets when reseating carb
Durability & Warranty
Expected Lifespan
Indefinite (non-consumable)
Warranty
Typically covered under manufacturer warranty if defective
Maintenance
Clean periodically with carburetor cleaner; no routine replacement needed
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