Sierra 18-99230 Ignition Switch Box for Mercury Mariner 2-Cylinder Outboard Engines

The Sierra 18-99230 is an ignition switch box built for 2-cylinder Mercury and Mariner outboard engines. The switch box is the component in the ignition circuit that manages spark delivery and timing to the powerhead, and it is a common wear/failure point on older Mercury and Mariner outboards when starting becomes inconsistent or the engine misfires or will not fire at all. Replacing the switch box with the Sierra 18-99230 restores the ignition circuit to factory-style operation without needing to source a hard-to-find original Mercury Mariner unit.

This part is identified by Sierra part number 18-99230, the manufacturer part number used for ordering and cross-checking against your engine's ignition system. It is built specifically for the 2-cylinder Mercury Mariner outboard platform, so it is intended as a direct functional counterpart to the factory switch box on those engines rather than a universal ignition component.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99230
• Product Type: Ignition Switch Box
• Compatible Engines: Mercury Mariner 2-cylinder outboard engines
• Weight: 0.8 pounds
• UPC: 808282393977

Fitment

• Mercury Mariner 2-cylinder outboard engines

Frequently Asked Questions

What is the Sierra 18-99230? It is an ignition switch box made for 2-cylinder Mercury Mariner outboard engines, used in place of the factory switch box in the engine's ignition circuit.

What engines does the Sierra 18-99230 fit? The Sierra 18-99230 is built for Mercury Mariner 2-cylinder outboard engines.

How much does the Sierra 18-99230 switch box weigh? The Sierra 18-99230 weighs 0.8 pounds.

What does an ignition switch box like the Sierra 18-99230 do? It manages spark delivery and timing to the powerhead, a role that is central to reliable starting and running on Mercury Mariner 2-cylinder outboards.

Is the Sierra 18-99230 a genuine Sierra part or a generic substitute? Sierra 18-99230 is the manufacturer part number for this switch box, so it is a genuine Sierra-branded component rather than an unbranded substitute.

What symptoms suggest a Mercury Mariner 2-cylinder engine needs a switch box like the 18-99230? Inconsistent starting, misfiring, or a complete failure to fire on a Mercury Mariner 2-cylinder outboard often point to a failing ignition switch box, the role the Sierra 18-99230 is designed to fill.

What is the UPC for the Sierra 18-99230? The UPC for the Sierra 18-99230 ignition switch box is 808282393977.

Does the Sierra 18-99230 fit outboards with more or fewer than 2 cylinders? No, the Sierra 18-99230 is built specifically for 2-cylinder Mercury Mariner outboard engines.

Can the Sierra 18-99230 be used to troubleshoot ignition problems? Since it replaces the switch box that controls spark timing on Mercury Mariner 2-cylinder engines, installing the 18-99230 is a common step when isolating ignition-related no-start or misfire issues.