SIERRA 18-7402 Ring Sterndrives 909140 919140 25-58390

( Brand: Sierra ), ( Manufacturer Part Number: 18-7402 ), ( Part Type: Ring Sterndrive )

Review SIERRA Replacement O ring Omc Sterndrives

Introducing the Sierra 18-7402 O-ring, a crucial component designed specifically for Omnicraft OMC sterndrives. This high-quality O-ring is engineered to provide an ideal seal, ensuring optimal performance and efficiency for your watercraft.

Measuring 25.5839 inches (650.11 mm) in length and fitting the part numbers 909140 and 919140, this O-ring is a must-have for boat owners who prioritize the reliability and functionality of their sterndrive system.

Manufactured using a durable, resilient rubber material, this O-ring is able to withstand the harsh marine environment and the heavy loads placed upon it. Its cross-section is a standard profile, providing the necessary sealing pressure to create a watertight seal between mating surfaces.

Installation of the Sierra 18-7402 O-ring is a straightforward process. Simply remove the old, worn-out O-ring from your OMC sterndrive, clean the area thoroughly, and carefully slide the new O-ring into place. Be sure to apply a light coating of clean marine grease to both sides of the O-ring before installation to ensure a smooth, even compression and a long-lasting seal.

With its precise dimensions and superior material quality, the Sierra 18-7402 O-ring is the perfect solution for maintaining the optimal performance of your Omnicraft OMC sterndrive. Order yours today and experience the peace of mind that comes with knowing your watercraft's most essential components are in top condition.

Pros and Cons of Buying O-Ring (Sierra 18-7402) for OMC Sterndrives

The Sierra 18-7402 o-ring is a critical component for OMC sterndrives. Replacing worn-out or damaged o-rings is essential for maintaining the efficient operation and longevity of your sterndrive system. In this analysis, we will discuss the advantages and disadvantages of purchasing this specific o-ring model.

1. Compatibility: The Sierra 18-7402 o-ring is explicitly designed for OMC sterndrives, ensuring a perfect fit and seamless performance.

2. Durability: Made from high-quality materials, this o-ring is resilient to wear and tear, promising extended service life.

3. Availability: The Sierra 18-7402 o-ring is widely available from various marine parts suppliers, making it easily accessible to boat owners.

4. Cost-effective: Compared to other o-ring models or complete gasket kits, purchasing this individual o-ring is a more affordable option for boat owners.

1. Limited flexibility: While the o-ring provides a snug fit, its limited flexibility may pose challenges during installation or removal, potentially requiring the use of specialized tools.

2. Manual replacement: Replacing the o-ring is a manual process, which can be time-consuming and may require some level of mechanical skill or expertise.

3. Potential for user error: Improper installation or removal of the o-ring could lead to leaks or other issues, necessitating the need for additional labor and parts.

The Sierra 18-7402 o-ring is an essential component for maintaining the optimal performance of OMC sterndrives. Its advantages, including compatibility, durability, availability, and cost-effectiveness, outweigh the disadvantages, such as limited flexibility, manual replacement, and potential for user error. By investing in a high-quality o-ring like the Sierra 18-7402, boat owners can save time and money in the long run by avoiding costly repairs or replacements.

We recommend purchasing the Sierra 18-7402 o-ring for your OMC sterndrive system. Ensure that you follow the manufacturer's installation instructions carefully to avoid any complications. Additionally, consider investing in a seal installation tool to make the process easier and more efficient.

Details:

Replaces OEM OMC 909140, Mercury Marine 25-58390, Sierra O-Ring, Pack of 5, This o-ring is for sterndrives. MPN: 18-7402. Brand: Sierra. Part number 18-7402.

Condition: New. Related Part Numbers: 909140, 25-58390.

part #: 187402 prices

• $5.89-$144.19

specifications otsterndriv:

• for makes: Omc
• brand: Sierra
• mpn: 18-7402
• part type: Ring Sterndrive

offer otsterndriv:

• sold: 0
• availability: In Stock
• options: Ship-to-home
• started: August 4, 2025
• quantity: 1
• best offers: True

payments otsterndriv:

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

returns otsterndriv:

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

general otsterndriv:

• condition: New
• Boat Parts > Sterndrive Motors Components > Other

shipping otsterndriv:

• type: Fixed
• cost: $0.00
• class: Standard, Expedited
• transit: 3-7 Days
• carrier: USPS
• service: Standard, USPS Priority Mail

seller otsterndriv:

• # reviews: 27725
• rating: 99.1%
• city: Green Bay, Wisconsin

Sierra 18-7402 Is Similar To:

• 18-0422 Sierra Gasket For Dist Cap Replaces Mercruiser (36.4% similar) Not all years use the same part number. Pen the package and inspect item for damage. Many used or no longer available items were pulled from our storage rooms at that time. If you reside in an EU member state besides UK, import vat on this purchase is not recoverable. Why wait for an offer listing ...(April 1st, 2019)
• 18-1172 Sierra Bearing Carrier Replaces Omc 030999974310 (31.3% similar) ...(January 20th, 2019)
• 18-2058 Sierra Oil Seal Omc Sterndrive 30999310095 (39.1% similar) Sierra oil seal omc sterndrive replaces: glam 86050MALLORY 9-76227OMC stern drive used on the following: model year hp 120FTHRCIF 1/1 20FTHRCIS 140FTHRCIF 140FTHRCIS 140SPHRCIF 140SPHRCIS 140STHRCIF 140STHRCIS 170SPMCCIF Spinx's suppressive spruces Styx's stammerers satirises featheriest 200FTHRCIS...(March 15th, 2019)
• 18-2180 Sierra International Marine Drive Shaft For Mercruiser Stern New (36% similar) Driveshaft for stern drive Mercuries...(March 29th, 2019)
• 18-2613 Sierra Outdrive Gasket Set Omc Cobra Stern Drive (38.8% similar) ...(September 22nd, 2018)
• 18-2664 Sierra Nos Lower Gearcase Seal Kit Replaces Omc 030999312754 (31.5% similar) If a part doesn't work for you any reason let us know...(September 25th, 2018)
• 18-2666 Sierra Upper Gear Housing Seal Kit Omc Stringer (37.6% similar) Customer needs to pay return shipping and items must be in brand new unused condition. Stock photos could be used in our listing. Pen the package and inspect item for damage. Why wait for an offer listing to end, when you can use the option and get coming. Many used or no longer available items were...(April 2nd, 2019)
• 18-2673 Sierra Upper Unit Seal Kit Omc Cobra 808282258023 (28.1% similar) E water cover gasket, replaces. E oil seal, replaces o o-ring. Sierra upper unit seal kit replaces oem omc, 986364, oil seal. E o-ring, replaces. E out drive gasket, replaces o o-ring, o-ring. E, 916058, 2541 rubber seal, replaces. Contains: water pump base gasket, replaces o housing. E seal, ...(October 7th, 2018)
• 18-2780 Sierra New Marine Exhaust Bellows Replaces Omc Cobra (34.8% similar) Brand new in package...(October 11th, 2018)
• 18-2875-9 Unbranded Sierra Gasket Replaces Omc Nos Jc (32.1% similar) Sierra gasket, replaces omc nos KC...(October 27th, 2018)
• 18-2912 Sierra Exhaust Manifold Gskt Replaces Omc Cobra Sterndrive Part (43% similar) Most items shipped USPS. Do not throw away the packaging, put package back together, it may need to be made available for inspection by carrier. They will not note the damage unless you point it out. Some new parts do not have their original box, or the box could be falling apart from age. Customer ...(March 13th, 2019)