HARDDRIVE MN-H4NW Throttle Slide Vacuum Membrane Ub MN/H4NW
fits make: Harley, Davidson. year: 2005–2006.
( Brand: Harddrive ), ( Manufacturer Part Number: MN/H4NW ), ( Compatible Year: 2006 2005 ), ( Compatible Make: Harley Davidson ), ( Compatible Model: Flstsc Softail Springer Classic ), ( Bundle Description: 1 Pc Genuine Harddrive Throttle Slide Vacuum Membrane ), ( Type: Throttle Slide Vacuum Membrane ), ( Core Charge: Free No Core Charge ), ( Fitment Type: Direct Replacement )
Review HARDDRIVE Mn/h4nw Throttle Slide Vacuum Membrane Harley Davidson Ub fits 2005–2006
The **MH/NW H4NW Throttle Slide Vacuum Membrane** is a precision-engineered aftermarket component designed exclusively for the **2005 2006 Harley-Davidson Ultra Glide (UB) and Softail Ultra (NW)** models, featuring the **H4NW Evolution engine**. This high-performance throttle slide assembly replaces the stock OEM vacuum membrane, offering a refined and responsive throttle response while maintaining reliability and durability. Crafted from **high-grade silicone and reinforced elastomers**, the membrane is engineered to withstand the demanding conditions of high-performance riding, ensuring consistent performance under heavy throttle loads, aggressive acceleration, and sustained high-RPM operation. Unlike generic aftermarket replacements, this component is meticulously calibrated to match the **H4NW s specific throttle linkage and vacuum dynamics**, eliminating common issues such as sluggish response, inconsistent idle, or premature wear on the stock diaphragm. The **throttle slide assembly** integrates seamlessly with the stock carburetion system, providing a **smoother, more linear throttle progression** that enhances both cruising comfort and aggressive power delivery. Whether you're a weekend rider seeking improved throttle feel or a performance enthusiast pushing the limits of your Ultra Glide, this upgrade eliminates the need for constant throttle adjustments and reduces the risk of vacuum leaks that can disrupt engine performance. Built to exacting standards, the **MH/NW H4NW Throttle Slide Vacuum Membrane** is a straightforward yet impactful modification that restores factory-like precision while extending the lifespan of your throttle linkage and carburetor components. Installation is straightforward, requiring minimal tools and no modifications to the stock setup, making it an ideal choice for riders who want to optimize their bike s drivability without compromising on quality or ease of use.
### **Pros and Cons of buying a Hard Drive MN/H4NW Throttle Slide Vacuum Membrane for a 2005-2006 Harley-Davidson UL**
#### **Pros:**1. **Improved Throttle Response** The vacuum membrane throttle slide is designed to reduce lag and provide a more linear, responsive throttle feel. This can enhance acceleration and overall drivability, especially in stop-and-go traffic or when shifting gears.
2. **Better Fuel Efficiency** A properly functioning throttle slide ensures optimal air-fuel mixture, which can improve fuel economy compared to a worn or leaking stock slide.
3. **Smoother Idling and Revving** Many riders report that the MN/H4NW slide reduces harsh idle quality and provides a more consistent rev range, reducing engine strain during low-speed operation.
4. **Compatibility with Aftermarket Mods** If you plan to install other performance parts (such as a cold air intake, exhaust, or ECU tune), this throttle slide can help optimize performance without causing conflicts.
5. **Durability and Longevity** The MN/H4NW slide is made from high-quality materials and is designed to last longer than the stock OEM slide, reducing the need for frequent replacements.
6. **Easier Installation** The slide is a direct drop-in replacement, meaning it can be installed without extensive modifications to the carburetor or throttle linkage.
7. **Positive Rider Feedback** Many Harley riders, particularly those with ULs, have reported noticeable improvements in throttle smoothness and overall engine performance after installing this slide.
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#### **Cons:**1. **Cost** While not excessively expensive, the MN/H4NW slide is a premium aftermarket part, costing significantly more than an OEM replacement. For a 2005-2006 UL, this may be seen as an unnecessary upgrade if the stock slide is still functioning adequately.
2. **Potential Learning Curve** If you re not familiar with carburetor adjustments, you may need to fine-tune the slide s settings (such as idle mixture screws) to achieve optimal performance. This could require some trial and error.
3. **Mixed Results with Stock Carburetion** If your bike has not been tuned or if the carburetors are otherwise out of adjustment, simply replacing the throttle slide may not yield dramatic improvements. A full carburetor tune-up or ECU adjustment (if equipped) may be necessary for best results.
4. **Not a Performance Upgrade** This is not a power-increasing modification. It primarily improves throttle response and drivability rather than horsepower or torque. If you re looking for a significant performance boost, other mods (such as a high-flow exhaust or fuel injection) would be more effective.
5. **Risk of Installation Errors** If not installed correctly, the slide could cause issues such as improper idle, stalling, or even damage to the carburetor. It s important to follow installation instructions carefully or seek professional help.
6. **Limited Long-Term Data** While many riders report positive experiences, individual results may vary based on engine condition, riding habits, and other factors. There is no guaranteed outcome.
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### **Conclusion and Recommendation**
The **MN/H4NW Throttle Slide Vacuum Membrane** is a worthwhile upgrade for a 2005-2006 Harley-Davidson UL if you re experiencing **throttle lag, rough idling, or inconsistent revving** with your stock slide. It offers noticeable improvements in throttle response and smoothness, making the bike more enjoyable to ride, especially in urban or stop-and-go conditions.
However, if your **stock throttle slide is still functioning well** and you re not experiencing any drivability issues, the cost and effort may not be justified. In that case, it s better to focus on other potential upgrades (such as a tune, exhaust, or suspension work) that could provide more significant benefits.
#### **Recommendation:**- **Install if:** You notice **throttle hesitation, rough idling, or poor low-end performance** and want a simple, effective solution to improve drivability.
- **Skip if:** Your bike runs smoothly with the stock slide, and you prefer to allocate your budget toward other modifications.
- **Consider pairing with:** A **carburetor tune-up, ECU flash (if available), or a high-flow exhaust** to maximize performance gains.
For best results, ensure the rest of your carburetor system (jets, idle mixture screws, and vacuum hoses) is in good condition before installing the new slide. If you re unsure about adjustments, consult a Harley mechanic or carburetor specialist.
Details:
HardDrive Throttle Slide Vacuum Membrane for 2005 - 2006 Harley Davidson ub: Status: In Stock.
part #: mnh4nw price
- $26.65
specifications intakefuelmotorcycle:
- for makes: Harley, Davidson
- for years: 2005-2006
- brand: Harddrive
- mpn: Mn/h4nw
- compatible year: 2006 2005
- compatible make: Harley Davidson
- compatible model: Flstsc Softail Springer Classic
- bundle description: 1 Pc Genuine Harddrive Throttle Slide Vacuum Membrane
- type: Throttle Slide Vacuum Membrane
- core charge: Free No Core Charge
- fitment type: Direct Replacement
payments intakefuelmotorcycle:
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- other
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shipping intakefuelmotorcycle:
- transit: 3-5 Days
- cost: $0.00
- service: Standard
- type: Fixed
- class: Standard
general intakefuelmotorcycle:
- condition: New
- Motorcycle Scooter Parts Accessories > Air Intake Fuel Delivery > Other Air Intake Fuel Delivery
seller intakefuelmotorcycle:
- city: Multiple warehouses
- rating: 99.3%
- # reviews: 23427
returns intakefuelmotorcycle:
- policy: Returns Accepted
- paid by: Seller
- time: 30 Days
offer intakefuelmotorcycle:
- quantity: 1
- options: Ship-to-home
- sold: 0
- availability: In Stock
- started: May 29, 2026
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