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Gaskets and Seals› O-rings, Grommets and Vacuum Caps

SIERRAMARINE

O-Ring

Name: O-Ring
Brand: SIERRAMARINE
SKU: S08C 18-7428-9

$7.99

SKU: S08C 18-7428-9

Free Shipping over $200

$100 Minimum Order

Non-Returnable Item

Overview

The Sierra Marine 18-7428-9 is an O-ring, priced per package of 2. Sealing the gap between two parts with an O-ring prevents leaks of fluids and gases.

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The Sierra Marine 18-7428-9 is a durable O-ring set, packaged as a set of two. It serves as a direct replacement for OEM part number 0307103, offering reliable performance and fitment. Its primary function is to maintain the integrity of the gearbox by sealing potential leak paths, contributing to the overall health and efficiency of the outboard motor.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

Brand	SIERRAMARINE
Part Number	S08C 18-7428-9
Category	Gaskets and Seals

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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