Your cart is empty
Start ShoppingMIKUNI F42-8 HSR 45/42 High Flow Carburetor Kit for Big Twin EVO & Twin Cam - Total Kit with Aluminum Body & Brass Jets
Fits your
May not fit your
Description
Elevate your motorcycle's performance with MIKUNI's premium HSR 45/42 Total Carburetor Kit. This high-flow system is engineered to deliver maximum power while maintaining optimal air-fuel balance for Big Twin EVO and Twin Cam models.
Key Features
- Aluminum Body & Brass Jets: Corrosion-resistant construction ensures long-lasting performance and precise fuel delivery.
- 45mm Main / 42mm Secondary Throttle Bore: Optimized airflow for enhanced horsepower without sacrificing engine efficiency.
- Complete Kit Inclusion: Includes intake manifold, air filter adapter, cables, and precision jets for seamless installation.
- High-Flow Filter Design: Minimizes restriction while supporting up to 100 horsepower gains for aggressive riding.
Why Choose This Product
Whether you're chasing speed or refining throttle response, this MIKUNI kit offers unmatched reliability and performance. The durable aluminum body resists warping, while brass slide and jets ensure smooth fuel metering. Perfect for riders seeking factory-level power without compromising engine longevity. Its universal fit for EVO and Twin Cam models makes it a versatile upgrade for street or track use.
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
Free Shipping $100+
14-Day Returns
Secure Checkout
Price Match
Complete the Build
This item
$964.27
In Cart
Elevate your motorcycle's performance with MIKUNI's premium HSR 45/42 Total Carburetor Kit. This high-flow system is engineered to deliver maximum power while maintaining optimal air-fuel balance for Big Twin EVO and Twin Cam models.
Key Features
- Aluminum Body & Brass Jets: Corrosion-resistant construction ensures long-lasting performance and precise fuel delivery.
- 45mm Main / 42mm Secondary Throttle Bore: Optimized airflow for enhanced horsepower without sacrificing engine efficiency.
- Complete Kit Inclusion: Includes intake manifold, air filter adapter, cables, and precision jets for seamless installation.
- High-Flow Filter Design: Minimizes restriction while supporting up to 100 horsepower gains for aggressive riding.
Why Choose This Product
Whether you're chasing speed or refining throttle response, this MIKUNI kit offers unmatched reliability and performance. The durable aluminum body resists warping, while brass slide and jets ensure smooth fuel metering. Perfect for riders seeking factory-level power without compromising engine longevity. Its universal fit for EVO and Twin Cam models makes it a versatile upgrade for street or track use.| SKU | GME5F5EF65 |
|---|---|
| MPN | F42-8 |
| Brand | MIKUNI |
| Category | Intake/Carb/Fuel System |
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 |
|---|---|---|
| Honda | CRF450R | 2009-2024 |
| Honda | CRF450RX | 2010-2024 |
| Honda | CRF250R | 2008-2024 |
| KTM | 450 SX-F | 2018-2024 |
| KTM | 350 SX-F | 2018-2024 |
Frequently Asked Questions
Primarily Honda CRF450R/RX (2009+), CRF250R (2008+), and KTM 350/450 SX-F (2018+). Check fitment tab for exact models.
Yes, includes main kit jetting for sea level. Re-jetting recommended for altitude/elevation changes.
Yes, professional tuning advised for optimal performance. Includes 5 different main jets.
Likely yes on new bikes. It's a performance upgrade replacing stock carb.
HSR45/42 carb, intake manifold, throttle cable, kill switch, air filter boot, complete jet kit, and hardware.
Installation Guide
Difficulty
Hard
Est. Time
2 hr 0 min
Tools Required
- socket set
- torque wrench
- carb cleaner
- screwdrivers
- jetting kit tools
- vacuum gauge
Pro Tips
- Bench sync carbs before install
- Use included jetting as starting point and tune with wideband O2 sensor
- Apply thread locker to idle mixture screw
Common Mistakes to Avoid
- Incorrect jetting leading to lean/rich conditions
- Not syncing throttle valves
- Damaging float bowl gasket during install
Comparison vs Stock/OEM
Replaces restrictive stock Keihin/PWK carburetors with larger flat-slide design
Improvements
- 30-40% more throttle response
- Better top-end power
- Easier tuning
- Smoother power delivery
Considerations
- Requires rejetting
- More expensive
- Professional tuning recommended
Durability & Warranty
Expected Lifespan
5+ years with proper jetting and maintenance
Warranty
1 year manufacturer defect warranty
Maintenance
Clean every 10 hours racing, inspect jets seasonally, sync annually
What Others Are Saying
Reviews from across the web
