Your cart is empty
Start ShoppingMIKUNI F4/042-580 Hex Main Jets - Precision Fuel Flow Control for High-Performance Engines
Fits your
May not fit your
Description
Upgrade your engine's fuel delivery system with MIKUNI's F4/042-580 Hex Main Jets. These precision-machined components deliver consistent fuel flow for enhanced throttle response, power output, and reliable performance across a wide range of riding conditions.
Key Features
- Hexagonal Design: Ensures secure fitment and precise fuel metering in MIKUNI carburetor systems
- High-Quality Brass: Durable construction resists corrosion and maintains accuracy under extreme temperatures
- Compatibility: Specifically engineered for MIKUNI carburetors with F4/042-580 specifications
- Easy Installation: Standardized threading simplifies replacement without specialized tools
Why Choose This Product
Whether you're fine-tuning a racing engine or optimizing your off-road rig, these main jets provide the critical fuel flow control needed for peak performance. Their precise engineering ensures consistent metering across wide-open throttle ranges, while the durable brass construction guarantees long-term reliability. Perfect for riders seeking to maximize power delivery without compromising engine longevity.
Delivery
Checking availability...
Estimated arrival
Order within to ship today
Orders ship
Shipping to
Enter your ZIP code for delivery estimate
Price Match Guarantee
Found it cheaper?
Log in to submit a price match request.
Price
Quantity
Purchasing is temporarily paused. You can still add items to your cart and check back soon.
Pay in 4 with
or
$0.00 x 4 interest-free
or
$0.00 x 4 interest-free
Free Shipping $100+
14-Day Returns
Secure Checkout
Price Match
Complete the Build
This item
$29.99
In Cart
Upgrade your engine's fuel delivery system with MIKUNI's F4/042-580 Hex Main Jets. These precision-machined components deliver consistent fuel flow for enhanced throttle response, power output, and reliable performance across a wide range of riding conditions.
Key Features
- Hexagonal Design: Ensures secure fitment and precise fuel metering in MIKUNI carburetor systems
- High-Quality Brass: Durable construction resists corrosion and maintains accuracy under extreme temperatures
- Compatibility: Specifically engineered for MIKUNI carburetors with F4/042-580 specifications
- Easy Installation: Standardized threading simplifies replacement without specialized tools
Why Choose This Product
Whether you're fine-tuning a racing engine or optimizing your off-road rig, these main jets provide the critical fuel flow control needed for peak performance. Their precise engineering ensures consistent metering across wide-open throttle ranges, while the durable brass construction guarantees long-term reliability. Perfect for riders seeking to maximize power delivery without compromising engine longevity.
| SKU | GM4CA1D5EB |
|---|---|
| MPN | F4/042-580 |
| Brand | MIKUNI |
| Category | Jets |
0.0
0 reviews
0
Log in to write a review.
Reviews
No reviews yet. Be the first to review this product!
Featured Review
| Make | Model | Years |
|---|---|---|
| Various (Mikuni VM/PF/BS series carbs) | TM/H/SN/BS carburetors | 1985-2024 |
| Yamaha | YZ250F/YZ450F | 2000-2010 |
| Honda | CR250R/CRF450R | 1998-2008 |
| KTM | SX/EXC 250/450 | 2004-2012 |
Frequently Asked Questions
Fits Mikuni VM26-VM34, PF, BS, TM, H, SN series round/flat slide carbs on 2-stroke/4-stroke dirt bikes, ATVs.
Yes, OEM-style hex main jet for factory Mikuni carbs; #580 size for richer mid-high fueling.
Often yes for complete rejetting after airbox/exhaust mods; this is main jet only.
Measure old jet with gauge or consult jetting chart based on mods/elevation.
Installation Guide
Difficulty
Easy
Est. Time
5 min
Tools Required
- Small flathead screwdriver
- Jet gauge (recommended)
Pro Tips
- Remove carb float bowl, unscrew old jet with screwdriver, note position. Use jet kit for full rejet. Verify size with micrometer.
Common Mistakes to Avoid
- Installing wrong size jet
- Not cleaning carb passages before install
Comparison vs Stock/OEM
Direct OEM replacement; identical to factory Mikuni jets
Improvements
- Precision machined for consistent flow
- Hex head for easy install/removal
Considerations
- None; exact spec match
Durability & Warranty
Expected Lifespan
Indefinite with proper jetting (no wear parts)
Warranty
Limited lifetime (Mikuni OEM)
Maintenance
Inspect during carb cleans; replace if clogged
What Others Are Saying
Reviews from across the web
