PYI INC Pss Shaft Seal Log Stern Tube 7/8 1/2 Log/stern 02-078-112

( Brand: Pyi Inc ), ( Manufacturer Part Number: 2078112 ), ( Color: 7/8 Inch Shaft Diameter ), ( Type: Other Type )

Review PYI INC Pss Shaft Seal 7/8 Inch And 1/2 Log/stern Tube

The **PYI 2078112 PSS Shaft Seal** is a high-performance, precision-engineered marine propulsion component designed to provide reliable sealing and lubrication for outboard and stern drive applications, specifically tailored for outboards manufactured between model years 2002 and 2007. This shaft seal is a critical component of the **Log/Stern Tube Assembly (02-078-112)**, ensuring a watertight barrier between the internal drive mechanism and the external environment while minimizing friction and wear. Constructed from durable, corrosion-resistant materials, the seal features a robust **carbon-graphite composite lip**, which maintains optimal sealing efficiency even under varying operating conditions, including exposure to saltwater, debris, and fluctuating temperatures. The design incorporates a **self-adjusting mechanism**, allowing it to accommodate slight misalignments or shaft movement without compromising performance, thereby extending both the seal s lifespan and the overall longevity of the propulsion system. Suitable for **7/8-inch diameter shafts**, this seal is engineered to fit seamlessly within the specified stern tube housing, preventing water ingress that could lead to electrical shorts, corrosion, or premature failure of the drive unit. Whether installed in recreational boats, fishing vessels, or small commercial craft, the PYI 2078112 PSS Shaft Seal delivers dependable protection, reducing maintenance requirements and ensuring smooth, efficient operation for years of reliable performance.

### **Pros and Cons of buying a PYI 2078112 PSS Shaft Seal (7/8" x 1/2" Log/Stern Tube, Part #02-078-112)**

1. **Compatibility with Common Engines** This shaft seal is designed for a wide range of marine outboard engines, particularly those from manufacturers like Yamaha, Mercury, and Suzuki, which often use this part number in their older models (2002 2007 range). If your engine is within this specification, it should fit without modification.

2. **Reliable Brand** PYI (Professional Yacht Industries) is a well-known manufacturer of marine seals, gaskets, and shaft sleeves. Their products are generally built to withstand the demands of marine environments, including saltwater corrosion and mechanical stress.

3. **Easy Installation** The design is straightforward, and many users report that replacing the seal is a manageable DIY task, especially with basic tools. The log/stern tube seal is typically accessed by removing the lower unit cover or stern gland, which is a common procedure for maintenance.

4. **Prevents Water Ingress** A properly installed shaft seal prevents water from entering the engine s lower unit, reducing the risk of corrosion, electrical shorts, and gear damage. This is critical for long-term engine health.

5. **Cost-Effective Alternative to Full Replacement** Replacing just the seal is often cheaper than overhauling the entire lower unit or replacing the outboard motor, especially if the rest of the engine is in good condition.

6. **Available from Multiple Sources** This part is widely stocked by marine supply stores, online retailers (e.g., Amazon, West Marine, BoatUS), and direct from PYI. Availability is generally not an issue unless you re dealing with a very obscure model.

7. **Durability** When installed correctly, PYI seals are known for lasting several years, especially in freshwater applications. In saltwater, they may require more frequent replacement due to corrosion.

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1. **Age of the Part Number** The part number **02-078-112** is associated with older engine models (2002 2007). If your engine is newer or from a different manufacturer, there s a chance the seal may not fit perfectly or may be outdated in design. Newer engines often use different materials (e.g., carbon graphite instead of traditional rubber) for better durability.

2. **Material Limitations** Traditional rubber or elastomer seals can degrade faster in saltwater compared to modern materials like carbon graphite, which are more resistant to corrosion and wear. If your boat is used in saltwater frequently, the seal may need replacement more often.

3. **Potential for Leaks if Improperly Installed** Even with the right part, leaks can occur if the seal is not installed correctly. This requires careful alignment, proper lubrication (often with grease), and ensuring the shaft is clean and undamaged. A poorly installed seal can lead to water leaks, which can damage the lower unit.

4. **Limited Lifespan in Harsh Conditions** In extreme conditions (e.g., heavy saltwater exposure, frequent high-speed use, or poor maintenance), the seal may wear out faster than expected. This could lead to unexpected downtime and additional costs.

5. **Compatibility Issues with Modified Engines** If your engine has been modified (e.g., shaft lengthened, different propeller fitment, or aftermarket lower units), the stock seal may not fit. Always verify the exact specifications of your engine s shaft and housing before purchasing.

6. **Price Sensitivity** While not excessively expensive, the cost of the seal itself ( $20 $50, depending on the source) may seem high if you re on a tight budget, especially if you also need to purchase additional tools (e.g., a seal installer tool) for proper installation.

7. **Risk of Counterfeit Parts** As with many marine parts, there is a risk of purchasing counterfeit or low-quality replicas, especially from untrusted online sellers. Always buy from reputable dealers to ensure authenticity.

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The **PYI 2078112 PSS shaft seal** is a solid, widely compatible choice for older marine outboard engines (2002 2007) from major brands. It offers a balance of reliability, ease of installation, and cost-effectiveness for basic maintenance. However, its suitability depends on your specific engine model, operating conditions (saltwater vs. freshwater), and installation skills.

If your engine is within the correct range and you re confident in your ability to install it properly, this seal is a practical and cost-efficient solution. For newer engines or those with modified lower units, you may need to verify compatibility or consider alternative seals (e.g., carbon graphite models).

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1. **Verify Compatibility** Double-check that your engine model (year, make, and lower unit type) matches the specifications for this seal. Consult your engine manual or contact the manufacturer if unsure.

2. **Choose the Right Material** If your boat operates primarily in saltwater, consider upgrading to a **carbon graphite seal** (e.g., PYI 02-078-112-CG) for longer lifespan and better corrosion resistance.

3. **Purchase from a Trusted Source** Buy the part from an authorized marine dealer, West Marine, or a reputable online retailer to avoid counterfeit or low-quality seals.

4. **Prepare for Installation** Gather the necessary tools (e.g., seal installer tool, grease, clean rags) and follow the manufacturer s installation instructions carefully to prevent leaks.

5. **Consider Professional Installation** If you re unsure about installing the seal yourself, have a marine mechanic perform the job to ensure a proper fit and seal.

6. **Monitor for Leaks** After installation, check for signs of water ingress (e.g., water in the lower unit, electrical shorts) and address any issues promptly.

**Final Verdict:** For the right engine and conditions, this seal is a **reliable and cost-effective choice**. However, always prioritize compatibility and installation quality to maximize its lifespan.

Details:

The PSS Shaft Seal can be easily retrofitted and is available for shafts ranging from 3/4. The stainless-steel rotor is used to compress the bellow before secured shaft with set-screws. This platform is now integrated and seamless. The stainless-steel rotor is sealed to the shaft by two O-rings that are recessed into bore of collar.

20mm to 150mm. Around the shaft and thus compensate for most misalignment vibration problems. The carbon flange is over-bored to the shaft diameter allowing it. Aside from these benefits, the PSS Shaft Seal helps to eliminate water in bilge 100% tight and wear propeller shaft.

The sealing surface is created between the flat surfaces of rotating stainless-steel rotor and stationary carbon flange. These O-rings rotate with the shaft and stainless-steel rotor do not experience wear during operation. Boat builders and boat yards recognize the advantages value of installing PSS as it eliminates maintenance, constant adjustment cost associated with traditional packing type glands. The stationary carbon flange is attached to the front side of bellow with hose clamps, and back end fits over Stern tube secured clamps.

The stainless-steel rotor is fit on the shaft in front of carbon flange. This compression pre-load maintains constant contact between the two flat faces of stainless-steel rotor and carbon flange, allowing PSS to compensate for variable fore aft movement due propeller thrust. The PSS Shaft Seal is a mechanical face seal.

part #: 2078112 prices

• $249.00-$578.85

specifications ignitionstartin:

• brand: Pyi Inc
• mpn: 2078112
• color: 7/8 Inch Shaft Diameter
• type: Other Type

shipping ignitionstartin:

• cost: $0.00
• service: Economy
• type: Fixed
• transit: 12-19 Days
• class: Economy

returns ignitionstartin:

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

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general ignitionstartin:

• Boat Parts > Inboard Engines Components > Ignition Starting Systems
• condition: New

offer ignitionstartin:

• availability: In Stock
• started: June 8, 2026
• options: Ship-to-home
• sold: 0
• quantity: 6

seller ignitionstartin:

• city: Wheeling, Illinois
• rating: 99.1%
• # reviews: 113202