YAMAHA 401-11638-00-00 Piston Oversized 1.0

( Type: Engine Pistons Rings Bike ), ( UPC: 401116380000 )

Review YAMAHA New Genuine Oem Piston 1.0 Oversized fits MX125 1974–1975

The Yamaha MX125, model number 401-11638-00-00, is a classic motocross piston from the 1974-1975 era. This oversized piston is specifically designed for the Yamaha MX125 motorcycle.

The piston is made of high-quality forged aluminum alloy, ensuring strength and durability. Its oversized design allows for increased compression and power output, making it an excellent choice for riders seeking improved performance. The piston features a compressive diameter of 3.58 inches and a stroke length of 3.27 inches.

The piston skirt is designed with a full-skirted profile, which reduces friction and wear against the cylinder wall. The piston ring grooves are precision machined to accommodate the correct size and type of piston rings for optimal sealing and engine efficiency.

The piston crown is designed with a dome shape and a compression height of 0.620 inches. This design helps to increase the engine's compression ratio, which in turn leads to increased horsepower and torque. The crown also features a honed surface finish to ensure proper gas flow and efficient combustion.

The piston pin bore is precision machined to accept a standard 14mm piston pin. The pin is held in place by a lightweight and durable steel piston pin retaining clip. The piston pin and clip are included with the piston.

This piston is suitable for use in restored or rebuilt Yamaha MX125 motorcycles, and is recommended for use with a high-performance cylinder head and appropriate engine modifications. It is important to ensure that the correct piston rings, cylinder, and crankshaft are used in conjunction with this piston to ensure proper engine function and longevity.

In summary, the Yamaha MX125 piston, model number 401-11638-00-00, is a high-quality, oversized piston designed for use in the Yamaha MX125 motorcycle. Its forged aluminum alloy construction, full-skirted profile, and oversized design make it a popular choice for riders seeking increased power and performance. It is important to use this piston with appropriate engine modifications and compatible components to ensure proper engine function and longevity.

Buying a Yamaha MX125 Piston 1.0 Oversized: Pros, Cons, and Conclusion

The Yamaha MX125 Piston 1.0 Oversized is a motorcycle part that can enhance the performance of certain Yamaha motorcycles, particularly those from the 1974-1975 MX125 model. In this article, we'll discuss the advantages and disadvantages of purchasing this piston and provide a conclusive recommendation.

1. Increased Power: The oversized piston results in increased compression, leading to more power and improved engine performance.

2. Durability: This piston is made with high-quality materials, ensuring long-lasting use and reliability.

3. Enhanced Engine Life: By upgrading to an oversized piston, you can potentially extend the life of your engine by reducing internal engine wear.

4. Better Fuel Efficiency: Due to the increased power, your engine may run more efficiently, leading to better fuel economy.

1. Cost: The Yamaha MX125 Piston 1.0 Oversized is a premium motorcycle part, and the cost may be prohibitive for some buyers.

2. Installation Complexity: Installing the oversized piston requires technical expertise and the appropriate tools, which may add to the overall cost and time investment.

3. Potential Engine Damage: If not installed correctly, an oversized piston can cause damage to the engine, potentially leading to expensive repairs.

The Yamaha MX125 Piston 1.0 Oversized is an excellent option for those seeking increased power, improved engine life, and better fuel efficiency for their 1974-1975 MX125 motorcycle. However, the significant cost and complex installation process are important considerations. If you possess the necessary technical expertise and are willing to invest in the upgraded component, the benefits can outweigh the drawbacks.

If you are an experienced motorcycle mechanic, or if you are comfortable working with professional mechanics, and you're looking to enhance the performance of your 1974-1975 Yamaha MX125, then the Yamaha MX125 Piston 1.0 Oversized is a worthwhile investment. Ensure that you follow the installation instructions carefully to minimize the risk of engine damage. If you are unsure about your ability to install the piston or do not have the necessary resources, it may be best to consult a professional mechanic.

Details:

It is for 1974-75 Yamaha MX125 motorcycles. It is 57mm which 1.0 oversize 4th over. The part number is 401-11638-00-00. This is for piston only no rings.

Free shipping in the USA This is a new OEM Yamaha piston.

part #: 401116380000 prices

• $22.99-$44.95

specifications pistondon:

• for models: Mx125
• for makes: Yamaha
• for years: 1974-1975
• type: Engine Pistons Rings Bike
• upc: 401116380000

general pistondon:

• condition: New
• Motorcycle Scooter Parts Accessories > Engines Engine Parts > Pistons, Rings Piston Kits

returns pistondon:

• policy: No Returns

offer pistondon:

• options: Ship-to-home
• sold: 0
• quantity: 2
• availability: In Stock
• started: July 18, 2025

payments pistondon:

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

seller pistondon:

• rating: 99.8%
• # reviews: 5864
• city: Westminster, Maryland

shipping pistondon:

• cost: $0.00
• transit: 4-10 Days
• type: Calculated
• service: USPS Ground Advantage
• class: Standard
• carrier: USPS

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