Description
Sierra 18-3703 Prop Nut is a precision-engineered, corrosion-resistant molded nylon prop nut designed primarily for Mercury and Mariner outboard engines. It serves as a direct original equipment manufacturer (OEM) replacement component to ensure secure propeller retention and reliable operation in harsh marine environments.
Engine Compatibility
This hardware component is compatible with the following specific outboard configurations:
- Mercury / Mariner 2-Stroke: 18 HP, 20 HP, and 25 HP engines manufactured in 1980 and newer.
- Mercury / Mariner 2-Stroke & 4-Stroke: 9.9 HP to 25 HP engines manufactured from 1986 and newer.
- Mercury 4-Stroke: F9.9 and F15 models.
- Mercury Bigfoot: 323cc Bigfoot 4-stroke outboards.
OEM & Interchange Numbers
The Sierra 18-3703 perfectly matches or exceeds original equipment specifications and interchanges with the following manufacturer part numbers:
- Mercury Marine: 11-88228
- Chrysler / Force / US Marine: 11-88228
- GLM: 21242
- Mallory: 9-73963
- Sears: 11-88228 or 11-882281
