YAMAHA 251-11638-00 Piston 4TH 1.0

( Manufacturer Part Number: 251-11638-00 ), ( Part Type: Piston ), ( Country Of Origin: United States ), ( Manufacturer Warranty: 30 Day ), ( Storage Location: J8 Crp1-n Buk 13 )

Review YAMAHA 4th Os 1.0 Piston New Oem fits AT1 1969–1971

The Yamaha AT1 4th 1.0 piston is a vital component for the restoration or customization of a Yamaha AT1 motorcycle from the 1969 to 1971 era. This piston, specifically model number 251-11638-00, is meticulously crafted to ensure optimal engine performance.

The piston is designed with a compression height of 33.0mm and a total height of 85.0mm, making it suitable for the specific engine specifications of the Yamaha AT1. The piston crown is engineered to provide an excellent compression ratio for enhanced power output and efficiency.

The piston skirt is designed to minimize friction and provide superior ring seal, ensuring a tight piston-to-cylinder fit. The piston also features a lightweight design, contributing to overall engine weight reduction for improved performance and fuel economy.

This piston is made from high-quality forged aluminum alloy for superior durability and heat resistance. The piston rings are also included in the package, ensuring a complete piston assembly for easy installation.

The 1.0 liter capacity of this piston makes it an ideal choice for Yamaha AT1 motorcycles with this engine size. By upgrading to a high-performance piston like the Yamaha 251-11638-00, riders can expect enhanced acceleration, improved fuel efficiency, and increased power output for a more exhilarating riding experience.

In summary, the Yamaha 251-11638-00 1969-1971 AT1 4th 1.0 piston is a top-quality, forged aluminum piston designed specifically for Yamaha AT1 motorcycles from the late 1960s to early 1970s. With its optimized compression ratio, lightweight design, and superior durability, this piston is an essential upgrade for any enthusiast looking to restore or customize their Yamaha AT1 motorcycle.

Considerations and Recommendation on Buying a Yamaha AT1 1.0 Piston (Model 251-11638-00) for 1969-1971 Motorcycles

The Yamaha AT1 1.0 Piston (Model 251-11638-00) is a popular replacement part for motorcycles from the 1969-1971 era. This piston is specifically designed for the 1.0L engine used in these motorcycles. In this analysis, we will discuss the pros and cons of purchasing this piston to help you make an informed decision.

1. High-quality material: The Yamaha AT1 1.0 Piston is made using top-tier materials, ensuring durability and excellent performance. This piston is forged from aluminum, which is known for its strength and lightweight properties.

2. Precision machining: The piston undergoes rigorous machining processes to ensure a perfect fit and optimal engine performance. The piston's surface finish is also crucial for reducing friction and improving engine efficiency.

3. Enhanced engine power: A worn-out piston can significantly impact engine performance. Replacing it with a new, high-quality piston such as the Yamaha AT1 1.0 Piston can result in improved power output and increased fuel efficiency.

4. Improved engine reliability: A faulty or worn-out piston can lead to various engine issues, including premature engine failure. By investing in a new piston, you can prevent potential engine problems and ensure long-term reliability.

1. Cost: Replacing a piston is a significant investment, especially for older motorcycles. The Yamaha AT1 1.0 Piston might be more expensive than aftermarket alternatives. However, the high-quality materials and precision machining justify the cost for many buyers.

2. Installation complexity: Installing a new piston can be a time-consuming and intricate process. It requires specialized tools and a good understanding of engine mechanics. Hiring a professional mechanic is recommended for most motorcycle owners.

3. Availability: Depending on your location, sourcing the Yamaha AT1 1.0 Piston might be challenging. It may not be readily available at your local motorcycle shop or online marketplaces. Contacting Yamaha's official dealership or authorized service centers is recommended.

The Yamaha AT1 1.0 Piston (Model 251-11638-00) is an excellent investment for owners of 1969-1971 motorcycles with a 1.0L engine. Its high-quality materials, precision machining, and potential performance improvements justify the cost. However, installation complexity and availability may be concerns for some buyers. To ensure a successful purchase and installation, it is recommended to source the piston from an official Yamaha dealership or authorized service center.

For owners of 1969-1971 Yamaha motorcycles with a 1.0L engine, we recommend considering the Yamaha AT1 1.0 Piston (Model 251-11638-00) as a replacement for a worn-out or faulty piston. Its high-quality materials and precision machining will ensure optimal engine performance and long-term reliability. Although the cost and installation complexity may be concerns, the benefits outweigh these factors for most motorcycle enthusiasts.

Details:

Spotlight: A Day Inside . Every part is one-of-a-kind. Its a crucial component for engine rebuilds, ensuring proper fit and performance vintage Yamaha motorcycles. Look for the Make Offer button on listing page.

This new OEM Yamaha 4th oversized 1.0mm piston is for 1969-1971 AT1 model's. We review all reasonable offers promptly. We started with a single motorcycle dismantled in home garage.: Are these genuine OEM parts?, Yes.

Do you combine shipping?, Yes. Do you accept offers?, Some listings offers. Please verify the part number and compatible model's before purchasing. To Watch.

Item must be in original, uninstalled condition with no modifications. 4.8 out of 5 stars across 322 reviews. FREE shipping on every order to the lower 48 states. Larger items from $46.99.

part #: 2511163800 prices

• $22.36-$38.99

specifications pistondon:

• for models: At1
• for makes: Yamaha
• for years: 1969-1971
• mpn: 251-11638-00
• part type: Piston
• country of origin: United States
• manufacturer warranty: 30 Day
• storage location: J8 Crp1-n Buk 13

shipping pistondon:

• cost: $0.00
• transit: 2-7 Days
• class: Standard, Expedited, One-day
• carrier: USPS, FedEx
• service: USPS Ground Advantage, USPS Priority Mail, FedEx 2Day, Overnight
• type: Fixed

payments pistondon:

• wallet: Apple-pay
• credit card: Mastercard
• other

returns pistondon:

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

seller pistondon:

• rating: 99.5%
• city: Odessa, Florida
• # reviews: 231095

general pistondon:

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

offer pistondon:

• started: May 21, 2026
• best offers: True
• quantity: 1
• availability: In Stock
• options: Ship-to-home
• sold: 0

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