BOYESEN MN-7H39 Reeds Fuel Air Ou MN/7H39

( Brand: Boyesen ), ( Manufacturer Part Number: MN/7H39 ), ( Color: Carbon Fiber ), ( Compatible Year: 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 ), ( Bundle Description: 1 Pc Genuine Boyesen Super Stock Reeds ), ( Type: Super Stock Reeds ), ( Core Charge: Free No Core Charge ), ( Fitment Type: Direct Replacement )

Review BOYESEN Mn/7h39 Super Stock Reeds Yamaha Fuel And Air Ou fits YZ85 2002–2017

The Boyesen MN/7H39 Reeds are a meticulously crafted, high-performance replacement for the fuel and air intake system on Yamaha YZ85 models produced between 2002 and 2017, designed to enhance both throttle response and engine efficiency. These reeds are engineered from durable, high-quality materials, ensuring long-lasting performance even under demanding riding conditions. The design incorporates a precise, balanced airflow pattern that optimizes fuel atomization and combustion, resulting in a more responsive and powerful engine output. The Boyesen MN/7H39 set features a sleek, aerodynamic shape that not only improves airflow but also reduces turbulence, allowing the engine to breathe more freely and maintain peak performance across a wide range of RPMs. Whether you're tearing through tight trails or cruising at high speeds, these reeds deliver a noticeable improvement in acceleration and overall engine smoothness. The installation process is straightforward, requiring minimal tools and time, making them an ideal upgrade for both seasoned mechanics and DIY enthusiasts. With their reputation for reliability and performance, the Boyesen MN/7H39 Reeds are a trusted choice for riders looking to unlock the full potential of their Yamaha YZ85 while preserving the stock engine s integrity.

### Pros and Cons of Buying Boyesen MN/7H39 Reeds for a 2002 2017 Yamaha YZ85 Fuel-Air Unit

1. **OEM Compatibility** Boyesen reeds are designed as direct replacements for the stock fuel-air units in Yamaha YZ85 engines, ensuring a seamless fit without modifications. This reduces the risk of installation errors or performance issues caused by mismatched parts.

2. **Improved Performance** The Boyesen reeds are often tuned to enhance throttle response, fuel efficiency, and power output compared to stock reeds. They can help the engine breathe better, especially under load, which may result in smoother acceleration and better high-RPM performance.

3. **Durability and Quality** Boyesen is a well-regarded brand in the off-road and performance tuning industry, known for producing durable reeds that resist wear and tear better than some aftermarket alternatives. Their reeds are typically made from high-quality materials to withstand the demands of high-RPM operation.

4. **Ease of Installation** Since these reeds are designed as direct replacements, swapping them out is a straightforward process that can often be done without specialized tools. This makes them a practical choice for riders who prefer simplicity and minimal downtime.

5. **Cost-Effective Upgrade** Compared to more extensive engine modifications (such as porting or upgrading the carburetor), Boyesen reeds offer a relatively inexpensive way to improve performance. They are often priced lower than other performance reed sets while still delivering noticeable benefits.

6. **Compatibility with Other Mods** If you plan to add other performance parts (e.g., a high-flow air filter, exhaust system, or clutch kit), Boyesen reeds can complement those upgrades without causing conflicts. They are a modular part that fits into a broader tuning strategy.

7. **Reliability** Boyesen products are known for their reliability in the aftermarket community. Riders often report that these reeds hold up well over time, especially when paired with proper maintenance (e.g., regular carburetor cleaning and fuel system checks).

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1. **Limited Tuning Flexibility** While Boyesen reeds improve performance, they are not as adjustable as some other aftermarket options (e.g., Keihin or Walbro carburetor kits with tunable jets). If you want fine-tuned control over fuel delivery, you may need to pair these reeds with additional modifications, such as a performance carburetor or ECU tuning.

2. **Potential for Voiding Warranty** If your Yamaha YZ85 is still under manufacturer warranty, installing aftermarket reeds (even OEM-compatible ones) may void the warranty. This is a risk to consider if you plan to keep the bike long-term or rely on dealer support.

3. **Mixed Reviews on Throttle Response** Some riders report that Boyesen reeds can make the throttle feel slightly "stiffer" or less responsive at low RPMs compared to stock reeds. This is subjective and may depend on the specific model year and riding style. A few users also mention that the transition between reeds and stock performance can be noticeable, requiring a break-in period.

4. **Fuel System Sensitivity** Like any performance modification, Boyesen reeds can make the engine more sensitive to fuel quality. If you use low-quality or ethanol-blended fuel, the reeds may clog more easily or cause running issues. This requires diligent maintenance, such as regular carburetor cleaning and using high-quality fuel additives.

5. **Not a "Set-and-Forget" Solution** While easier to install than some mods, Boyesen reeds still require proper setup. If the carburetor jets are not balanced correctly, you may experience issues like flooding, lean conditions, or poor idle. This may necessitate adjustments to the carburetor or fuel system.

6. **Potential for Over-Tuning** If you re already running other performance parts (e.g., a high-flow air filter or exhaust), adding Boyesen reeds without adjusting the rest of the setup could lead to an overly rich or lean mixture. This might result in reduced reliability or increased wear on the engine.

7. **Availability and Fitment Variability** While Boyesen offers a wide range of products, fitment can vary slightly between model years of the YZ85. Double-checking that the MN/7H39 reeds are explicitly listed for your year is crucial, as some riders have reported minor fitment issues or the need for additional gaskets.

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Boyesen MN/7H39 reeds are a solid, OEM-compatible choice for upgrading the fuel-air unit on a 2002 2017 Yamaha YZ85. They offer a straightforward way to improve throttle response, power, and reliability without requiring extensive modifications. The brand s reputation for durability and ease of installation makes them a practical option for riders looking for a mid-range performance boost.

However, they are not without trade-offs. The lack of adjustability, potential warranty implications, and the need for proper fuel system maintenance are factors to consider. Additionally, if you re planning a more aggressive tuning approach (e.g., porting, ECU tuning, or a full carburetor swap), these reeds may need to be paired with other modifications to avoid imbalance.

For most riders seeking a simple, effective upgrade that enhances performance without major hassle, Boyesen reeds are a recommended choice. If you re already running other performance parts or prioritize extreme tunability, you may want to explore alternatives like a full carburetor kit or high-performance reeds from brands like Walbro or Keihin.

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If you re looking for a **direct, no-fuss upgrade** to improve your YZ85 s power and throttle response, the Boyesen MN/7H39 reeds are a **strong recommendation**. They strike a balance between cost, ease of installation, and performance gains. To maximize their effectiveness:

- Use **high-quality fuel** and consider a fuel stabilizer or additive.

- Ensure the **carburetor jets are properly balanced** (you may need to adjust them slightly after installation).

- Pair them with **other complementary mods** (e.g., a high-flow air filter or exhaust) if you want further gains.

- Monitor the engine s behavior during the **break-in period** (first 5 10 hours of use) to ensure smooth operation.

If you re unsure about carburetor tuning or want more flexibility, you might explore a **performance carburetor kit** (e.g., Walbro or Keihin) in the future. But for most riders, Boyesen reeds are a **wise and practical investment**.

Details:

Boyesen Super Stock Reeds for 2002 - 2017 Yamaha YZ85 - Fuel Air ou: Status: In.

part #: mn7h39 prices

• $28.83-$55.85

specifications intakefuelmotorcycle:

• for models: Yz85
• for makes: Yamaha
• for years: 2002-2017
• brand: Boyesen
• mpn: Mn/7h39
• color: Carbon Fiber
• compatible year: 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005
• bundle description: 1 Pc Genuine Boyesen Super Stock Reeds
• type: Super Stock Reeds
• core charge: Free No Core Charge
• fitment type: Direct Replacement

offer intakefuelmotorcycle:

• options: Ship-to-home
• sold: 0
• started: February 8, 2026
• availability: In Stock
• quantity: 1

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• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

seller intakefuelmotorcycle:

• # reviews: 17258
• rating: 98.7%
• city: Multiple warehouses

shipping intakefuelmotorcycle:

• class: Standard
• type: Fixed
• service: Standard
• transit: 3-5 Days
• cost: $0.00

general intakefuelmotorcycle:

• Motorcycle Scooter Parts Accessories > Air Intake Fuel Delivery > Other Air Intake Fuel Delivery
• condition: New

payments intakefuelmotorcycle:

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