5039-W322598-89 WSM Piston Kit Yamaha

Review WSM Piston Kit 636cc 0.25mm Oversize To 77.25mm Bore For Yamaha for YAMAHA 1990–1993

Introducing the WSM 5039-W322598-89 piston kit, specifically designed for Yamaha engines with a displacement of 636cc and a stroke length of 77.25mm, manufactured for use in the models produced between 1990 and 1993. This piston kit is an essential upgrade for those seeking improved engine performance, durability, and longevity.

Each piston in this kit is meticulously crafted using high-quality forged aluminum alloy, ensuring superior strength and rigidity. The piston crown is precisely machined to provide optimal combustion chamber shape and size, ensuring efficient fuel burn and optimal power output. The piston skirt is designed with a 0.25mm over-size to provide a better seal in the cylinder bore, leading to reduced engine blow-by and improved power delivery.

The WSM 5039-W322598-89 piston kit also includes matching piston rings, ensuring a perfect seal between the piston and the cylinder bore. The rings are made from high-tensile steel and are precision-machined to provide a snug fit and maximum compression.

This piston kit comes with all necessary hardware, including piston pins, clips, and retaining rings, making the installation process hassle-free. Each component is inspected and tested to ensure the highest level of quality and reliability.

In summary, the WSM 5039-W322598-89 piston kit is an excellent upgrade for those seeking improved power, durability, and efficiency in their Yamaha engine. The use of high-quality materials, precision machining, and comprehensive hardware package ensures a seamless installation and outstanding performance.

Piston Kit (WSM 5039-W322598-89) for 1990-1993 Yamaha: Pros, Cons, and Recommendation

The WSM 5039-W322598-89 piston kit is a popular replacement option for the 636cc, 0.25mm, 77.25mm piston application on 1990-1993 Yamaha motorcycles. Let's examine the advantages and disadvantages of purchasing this piston kit.

1. OEM Quality: This piston kit is manufactured by Warr's Summit Manufacturing (WSM), which is a well-known and reputable aftermarket parts supplier. The pistons are designed to meet or even exceed the original equipment manufacturer (OEM) specifications.

2. Improved Performance: Upgrading to this piston kit can potentially lead to increased power and torque, enhancing the overall riding experience.

3. Longer Service Life: The pistons are engineered with high-quality materials and advanced technology, ensuring a longer service life compared to the OEM pistons.

4. Cost-Effective: Buying a piston kit like this can save money in the long run, as it includes multiple pistons and other necessary components, as opposed to purchasing individual parts.

1. Installation Complexity: Installing a piston kit involves removing the engine cylinder head and other components, which can be a complicated and time-consuming process. It is recommended to have the work done by a professional mechanic or follow detailed instructions from a reputable source.

2. Potential Compatibility Issues: Although the piston kit is designed for 1990-1993 Yamaha models, it's essential to double-check the compatibility with the specific motorcycle make, model, and engine size to ensure a proper fit.

The WSM 5039-W322598-89 piston kit offers several advantages, including OEM quality, improved performance, longer service life, and cost-effectiveness. However, it comes with some drawbacks, such as the complex installation process and potential compatibility issues.

If you're looking to upgrade your motorcycle's pistons and are confident in your mechanical abilities or have access to a skilled mechanic, the WSM 5039-W322598-89 piston kit is an excellent choice. Ensure that you've verified the compatibility with your specific motorcycle before purchasing and installation.

Details:

Parts without fitment are to be assumed universal and may require vehicle modification. I need to exchange an item.: brand: Wsm, model number: 5039-W322598-89. This is helpful if you are buying multiple items.

Wsm piston kit 636cc -0.25mm oversize to 77.25mm bore for 1990 - 1993 Yamaha sj650 super jet ski: bore: 77.25mm, sizing: 0.25mm. Wsm standard series piston kit contains: 1 one piston as well rings, pin and clips to match piston bore size: 77.25mm, actual contents may vary from photo, quality construction are exact oem specifications. Compatibility: years: make: model: application: notes: 1990 - 1993 Yamahasj650 super jet, 1996 Yamahawra650 wave runner iii, 1993 Yamahawr650 LX, 1991 1995 Yamahawrb650 VCR.

specifications watercraftimp:

• for makes: Yamaha
• for years: 1990–1993
• brand: Wsm
• mpn: 5039-w322598-89
• part type: Piston

payments watercraftimp:

• credit card: mastercard
• other
• wallet: apple-pay

general watercraftimp:

• category: Watercraft Parts > Engines > Impellers Components

seller watercraftimp:

• # reviews: 84728
• rating: 99.9%
• city: boise, id

offer watercraftimp:

• started: may 7, 2026
• price: $81.14
• item condition: New
• availability: in stock
• sold #: 15
• in stock #: 1
• options: ship-to-home

shipping watercraftimp:

• class: standard
• service: standard
• type: fixed
• transit: 3-6 days

returns watercraftimp:

• time: 30 days
• paid by: seller
• policy: returns accepted