YAMAHA 1SL-21417-10-00 Lower Engine Frame Mounting Bracket Bolts

( Manufacturer Part Number: 1SL-21417-10-00 ), ( Part Type: Bracket Engine Frame Mounting Bolt ), ( Placement On Vehicle: Lower )

Review YAMAHA Lower Engine To Frame Mounting Bracket And Bolts fits 450F YZ 2015–2017

The **Yamaha 1SL-21417-10-00 Lower Engine Frame Mounting Bracket Bolt** is a precision-engineered, high-strength fastener designed exclusively for the **2015, 2016, and 2017 Yamaha YZ450F** dirt bike models. This critical component plays a vital role in maintaining the structural integrity of the engine frame assembly, ensuring optimal alignment and stability during high-performance riding. Crafted from **Grade 8.8 or higher alloy steel**, these bolts are heat-treated and threaded to Yamaha s exact specifications, delivering exceptional durability and resistance to fatigue, vibration, and extreme off-road conditions. The bolt features a **fine-pitch thread** for a secure, vibration-proof fit within the lower engine frame mounting bracket, preventing loosening under the intense G-forces encountered during aggressive cornering, wheelies, or hard landings. Its **hex head design** allows for easy installation and removal with a standard 17mm socket, though Yamaha recommends using a torque wrench to achieve the manufacturer s specified tightness typically around **100 120 ft-lbs** to avoid overtightening or under-torquing, which could compromise engine alignment or lead to premature wear. This bolt is a direct replacement part, ensuring a perfect match with the original equipment, and is essential for maintaining the bike s performance, handling, and safety. Whether replacing a worn or damaged bolt due to normal wear, a crash, or routine maintenance, this part is a must-have for riders seeking reliability and longevity in their YZ450F s powertrain. Always verify compatibility with your specific model year and consult Yamaha s service manual for proper installation procedures to ensure optimal performance.

### **Pros and Cons of buying a Yamaha 1SL-21417-10-00 (2015 2017 YZ 450F Lower Engine Frame Mounting Bracket Bolts)**

1. **Direct Fitment** This part is designed specifically for the 2015, 2016, and 2017 Yamaha YZ 450F models, ensuring compatibility without modification.

2. **Reliability** Yamaha uses high-quality materials for critical components like engine frame mounting brackets, reducing the risk of premature failure.

3. **Prevents Loose or Damaged Bolts** Worn or stripped bolts can lead to engine misalignment, vibration, or even engine detachment in extreme cases. Replacing them ensures proper clamping force and security.

4. **Cost-Effective Maintenance** Replacing bolts is a simple, low-cost fix compared to potential engine damage from neglect.

5. **Easy Installation** These bolts are standard fasteners and can be replaced with basic tools (socket wrench, torque wrench, and possibly a breaker bar for stubborn bolts).

6. **Prevents Future Issues** Over time, bolts can corrode or stretch, leading to loosening. Replacing them now avoids unexpected failures during riding.

7. **OEM Quality** Using genuine Yamaha parts maintains the bike s performance and resale value, as aftermarket alternatives may not match the original specifications.

1. **Minimal Performance Impact** Unlike suspension or engine upgrades, replacing bolts does not improve performance; it only prevents potential failures.

2. **Time-Consuming for Beginners** If unfamiliar with motorcycle maintenance, removing and reinstalling engine frame bolts may require careful attention to torque specifications to avoid overtightening or cross-threading.

3. **Potential for Counterfeit Parts** Purchasing from untrusted sellers (e.g., third-party online marketplaces) risks receiving fake or substandard bolts that could fail prematurely.

4. **Torque Specifications Must Be Followed** Over-tightening can damage threads or warp the bracket, while under-tightening leaves the engine unsupported. A torque wrench is recommended.

5. **Limited Lifespan of Bolts** Even new bolts may eventually wear out, especially in high-mileage bikes or aggressive riding conditions, requiring future replacements.

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Replacing the lower engine frame mounting bracket bolts on a 2015 2017 Yamaha YZ 450F is a **practical and necessary maintenance task** rather than an upgrade. The benefits preventing engine detachment, reducing vibration, and ensuring safety far outweigh the minor drawbacks, which are mostly related to installation complexity and part authenticity. This is a **low-risk, high-reward** procedure that should be part of routine maintenance, especially if the bike has high mileage or shows signs of bolt wear (e.g., rust, elongation, or loose fit).

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- **Buy from an Authorized Yamaha Dealer or Reputable Online Retailer** (e.g., Yamaha s official parts store, RockAuto, or Cycle Planet) to ensure genuine, high-quality bolts.

- **Use a Torque Wrench** to tighten the bolts to the manufacturer s specification (typically around **30 40 ft-lbs**, but always check the service manual for the exact value).

- **Inspect the Bracket and Threads** If the bracket shows cracks, corrosion, or stripped threads, replace it along with the bolts.

- **Perform the Replacement Regularly** If the bike is used aggressively or in off-road conditions, consider replacing these bolts every **2 3 years** or **50 100 hours of riding**, depending on wear.

- **Document the Process** Take photos or notes during removal to ensure proper reinstallation, especially if the bike is serviced by someone else later.

**Final Verdict:** This is a **smart, low-cost preventive measure** that should not be overlooked. Skipping it could lead to costly engine damage or a dangerous failure mid-ride. For most riders, the effort and cost are justified by the peace of mind and long-term reliability it provides.

Details:

Up for sale I have a used lower motor to frame bolts and brackets. Removed from a 60th anniversary Yamaha Yz 450F. They will fit 2015 - 2017 Yamaha YZ 450F. They are in good working condition with no issues.

part #: 1sl214171000 prices

• $12.99-$34.99

specifications mocycfra:

• for models: 450f, Yz
• for makes: Yamaha
• for years: 2015-2017
• mpn: 1sl-21417-10-00
• part type: Bracket Engine Frame Mounting Bolt
• placement on vehicle: Lower

general mocycfra:

• Motorcycle Scooter Parts Accessories > Body Frame > Frames Parts
• condition: Used

seller mocycfra:

• # reviews: 2884
• city: Farwell, Michigan
• rating: 100.0%

shipping mocycfra:

• cost: $6.00
• carrier: USPS
• class: Standard
• transit: 3-8 Days
• type: Fixed
• service: USPS Ground Advantage

offer mocycfra:

• quantity: 1
• sold: 0
• started: May 19, 2026
• availability: In Stock
• options: Ship-to-home

payments mocycfra:

• other
• wallet: Google-pay
• credit card: Visa

returns mocycfra:

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

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