YAMAHA 5CU-17131-01-00 Engine Transmission Gears

( Manufacturer Part Number: 5CU-17131-01-00 ), ( Type: Transmission )

Review YAMAHA Oem Engine Transmission Tranny Assembly Gears fits YZ250 1926–1999

The **Yamaha 5CU-17131-01-00 (99-26 YZ250 Engine Transmission Gears)** is a meticulously engineered set of transmission components designed exclusively for Yamaha s iconic 250cc YZ250 models produced between the years 1999 and 2006. This high-performance gear assembly plays a critical role in the engine s drivetrain, ensuring seamless power transfer from the crankshaft to the rear wheel while maintaining optimal shifting precision and durability. Crafted from Yamaha s proprietary materials, these gears are precision-machined to exacting tolerances, featuring hardened steel construction to withstand the intense forces generated during high-revving, aggressive riding conditions. The gear set includes a carefully balanced combination of input, output, and idler gears, each designed to minimize friction, reduce wear, and maximize efficiency allowing the engine to deliver its full potential in both off-road and competitive racing scenarios. Whether used for restoration projects, performance upgrades, or routine maintenance, this genuine OEM gear set ensures compatibility with the YZ250 s clutch and transmission system, guaranteeing reliable operation and extended component life. Ideal for riders seeking to restore stock performance or enhance their bike s drivetrain, this part exemplifies Yamaha s commitment to quality and engineering excellence in off-road motorcycling.

**Pros and Cons of Buying a Used Yamaha 5CU-17131-01-00 (99-26 YZ250 Engine with Transmission Gears)**

### **Pros**

1. **Cost-Effective Replacement** Purchasing a used engine and transmission assembly is significantly cheaper than buying new parts, making it a practical solution for budget-conscious riders or those restoring older YZ250 models.

2. **Compatibility** The 5CU-17131-01-00 engine is designed specifically for the 1999-2006 Yamaha YZ250, ensuring a direct fit without modification. This eliminates the need for customization or additional parts.

3. **Performance Retention** If the engine and transmission are in good condition, they will provide reliable performance similar to a new unit, allowing the bike to run smoothly without major power loss.

4. **Easier Restoration** For bikes that have been neglected or damaged, replacing just the engine and transmission (rather than the entire bike) can be a more straightforward and cost-effective restoration project.

5. **Accessibility of Parts** Yamaha engines and transmissions are widely available in the aftermarket, making it easier to find replacement parts or additional components if needed.

6. **Potential for Customization** Some riders may opt for upgraded internals (e.g., pistons, crankshafts, or clutch components) to enhance performance, which can be done more affordably with a used engine.

7. **Environmental Benefit** Buying used reduces waste and supports recycling of mechanical components, which is beneficial for sustainability.

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### **Cons**

1. **Unknown Service History** Without a clear maintenance record, it s difficult to determine if the engine and transmission have been properly serviced, overhauled, or abused. Hidden issues like worn bearings, seized components, or internal damage could lead to premature failure.

2. **Potential Wear and Tear** Used parts may already have some internal wear, such as worn piston rings, clutch plates, or transmission gears. This could result in reduced efficiency, increased oil consumption, or poor shifting performance.

3. **Risk of Hidden Damage** Even if the engine and transmission look externally sound, internal damage (e.g., cracked casings, bent crankshafts, or seized bearings) may not be visible until the unit is disassembled or tested under load.

4. **Limited Warranty or No Warranty** Used parts typically come with no warranty, meaning you bear all responsibility for repairs if issues arise. This can be a financial risk if the parts fail shortly after installation.

5. **Compatibility with Other Components** While the engine and transmission are compatible with the YZ250 frame, other components (e.g., carburetor, exhaust, or electrical system) may need updating or replacement to ensure optimal performance. Ignoring this could lead to mismatched power delivery or drivability issues.

6. **Time-Consuming Installation** Replacing an engine and transmission requires significant mechanical skill, time, and tools. If you re not experienced, the process could be challenging, and mistakes could lead to further damage.

7. **Resale Value Concerns** If you plan to sell the bike later, a used engine and transmission may deter buyers who prefer a fully restored or original setup. This could reduce the bike s resale value.

8. **Potential for Counterfeit or Mismatched Parts** There is a risk of purchasing a replica or mismatched part, especially if buying from untrusted sources. This could lead to compatibility issues or poor performance.

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### **Conclusion**

Buying a used Yamaha 5CU-17131-01-00 engine and transmission for a 1999-2006 YZ250 can be a **cost-effective and practical solution** for riders on a budget or those undertaking a restoration project. The parts offer direct compatibility and can significantly reduce expenses compared to new components. However, the **lack of warranty, unknown service history, and potential for hidden damage** pose risks that must be carefully considered.

To mitigate these risks, **thoroughly inspect the parts** (or have a mechanic do so) for signs of wear, test them for smooth operation, and ensure they are sourced from a reputable dealer or trusted seller. Additionally, consider **upgrading complementary components** (e.g., clutch, carburetor, or exhaust) to maximize performance and reliability.

If you are **mechanically inclined, willing to invest time in inspection and installation, and can afford the potential risks**, purchasing a used engine and transmission can be a smart financial decision. However, if you prioritize **long-term reliability, warranty protection, and ease of installation**, investing in a **new or high-quality rebuilt unit** may be the safer choice.

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### **Recommendation**

- Purchase from a **trusted source** (e.g., a reputable bike parts dealer, auction with inspection options, or a mechanic who can verify condition).

- **Inspect or test the engine and transmission** before buying (e.g., check for leaks, unusual noises, or smooth operation under load if possible).

- **Budget for additional components** (e.g., clutch, seals, or transmission fluid) to ensure everything functions correctly.

- **Consider a rebuild kit** if you plan to overhaul the engine yourself, as this can extend its lifespan.

- Opt for a **new or factory-rebuilt Yamaha engine and transmission** from an authorized dealer. While more expensive, it comes with warranty coverage and guaranteed performance.

- If cost is a concern, look for **high-quality aftermarket rebuilt units** from trusted brands (e.g., Yamaha Performance Parts or reputable rebuilders).

- Hire a **professional mechanic** to inspect and install the parts to avoid costly mistakes.

- Consider **buying a complete restored bike** instead of individual components if your goal is a fully functional machine.

Ultimately, the best choice depends on your **budget, mechanical skill level, and willingness to take risks**. For most riders seeking a balance of cost and reliability, a **used unit from a verified source with careful inspection** can be a viable option, provided you are prepared for potential follow-up repairs.

Details:

Fitment: Check the compatibility section above to make sure this part fits your specific bike.

part #: 5cu171310100 prices

• $59.99-$70.59

specifications transmissioncycleoi:

• for models: Yz250
• for makes: Yamaha
• for years: 1926-1999
• mpn: 5cu-17131-01-00
• type: Transmission

offer transmissioncycleoi:

• sold: 0
• availability: In Stock
• quantity: 1
• options: Ship-to-home
• started: June 4, 2026

returns transmissioncycleoi:

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

seller transmissioncycleoi:

• city: Grand Rapids, Michigan
• rating: 100.0%
• # reviews: 839

general transmissioncycleoi:

• condition: Used
• Motorcycle Scooter Parts Accessories > Transmission Drivetrain > Other Transmission Drivetrain Parts

shipping transmissioncycleoi:

• class: Standard
• transit: 4-7 Days
• service: Standard
• cost: $0.00
• type: Fixed

payments transmissioncycleoi:

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

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