Sierra Timing Protection Module 18-99265, OEM 857169T2 Equivalent for Mercury Mariner V6 Outboards

The Sierra 18-99265 Timing Protection Module is an electrical component built for Mercury Mariner V6 outboard engines, designed to safeguard the engine's ignition timing during operation. Housed in a blue aluminum enclosure, the module uses a transom-mount design and operates electrically, making it a direct fit for gasoline-fueled 4-stroke outboard installations. It is well suited for recreational boaters who rely on their outboard for fishing, cruising, and water sports, giving the ignition system a dependable layer of timing protection. At 0.8 pounds, the module is compact and straightforward to mount within the outboard's electrical housing during a repair or preventive replacement. Buyers replacing a worn or failed timing module can use the Sierra 18-99265 as a cross-reference to several OEM part numbers, simplifying the search for the correct replacement component. The aluminum housing is built to withstand the marine engine environment while protecting the internal electronics from vibration and heat. Whether restoring an aging V6 outboard to full working order or performing routine maintenance on the ignition system, this module is a targeted, application-specific part rather than a universal fit.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99265
• Application: Mercury Mariner V6 Outboard Engines
• Weight: 0.8 pounds
• Color: Blue
• Material: Aluminum
• Mounting Type: Transom Mount
• Engine Type: 4 Stroke
• Operation Mode: Electric
• Fuel Type: Gasoline
• OEM Cross-Reference: 857169A2, 857169T1, 857169T2, R857169T2

Fitment

Fits Mercury Mariner V6 outboard engines.

Replaces (OEM)

857169A2, 857169T1, 857169T2, R857169T2

Frequently Asked Questions

What does the Sierra 18-99265 timing protection module do? It protects the ignition timing on Mercury Mariner V6 outboard engines, serving as an electrical safeguard component within the engine's ignition system.

Will the 18-99265 fit my Mercury Mariner outboard? The Sierra 18-99265 is built for Mercury Mariner V6 outboard engines; it is not a universal part, so confirm your engine is a V6 Mercury Mariner model before ordering.

What OEM part numbers does the 18-99265 cross-reference to? It cross-references to OEM numbers 857169A2, 857169T1, 857169T2, and R857169T2, so any of these part numbers point to the same replacement application.

How much does the timing protection module weigh? The Sierra 18-99265 weighs 0.8 pounds.

What material is the module housing made from? The housing is made from aluminum, finished in blue.

Is this an electric or manual component? The 18-99265 operates electrically and uses a transom-mount installation design.

What fuel type and engine cycle is the module designed for? It is designed for gasoline-fueled, 4-stroke outboard engines.

Is the Sierra 18-99265 a genuine Sierra part or aftermarket? The 18-99265 is sold under the Sierra part number and is built as a direct cross-reference replacement for the listed OEM timing protection module numbers.

What boating activities is this module suited for? It is intended for recreational boating uses such as fishing, cruising, and water sports on Mercury Mariner V6 outboard-powered boats.

Can I install the 18-99265 myself? The module mounts to the outboard's electrical housing using a transom-mount design, though installation should follow the engine's electrical system service procedures.