Tutor Auto Boat Ignition Switch for Mercury/Mariner — 3-Position 6-Wire with 2 Keys, Corrosion-Resistant

The Tutor Auto 87-17009A5/87-17009A2 replacement ignition switch restores reliable start, stop and choke control for compatible Mercury and Mariner outboard motor control boxes.

If your boat’s key is hard to turn, the engine won’t respond, or the choke function is intermittent, replacing the ignition switch is often the simplest fix. This direct-replacement, 6-wire ignition key switch from Tutor Auto is designed to match common Mercury/Mariner control boxes (OE numbers 87-17009A5, 87-17009A2, MP51090, MP41070-2, MP41070-1) and comes with two keys and clear factory-color wiring to simplify installation.

How does this ignition switch improve starting and choke control?

Replacing a worn or corroded switch with this unit restores the three-position operation (Off – On/Ignition – Start) and the push-to-choke function so your motor responds predictably. The switch uses brass contacts for conductivity and polyester housing for corrosion resistance, helping maintain consistent electrical connections in marine environments.

• Three positions: Off, Ignition/On, and Start for normal operation.
• Push-to-choke wiring supports choke activation during cold starts.
• Brass contact points for improved conductivity and reliability.
• Corrosion-resistant polyester housing protects internal parts from saltwater exposure.

Will this part fit my Mercury or Mariner outboard control box?

This Tutor Auto switch is a direct replacement for several common Mercury OE part numbers; confirm the part number on your existing switch before ordering. The wiring harness follows the factory color code so it aligns with the original harness and control box connections.

• Replaces Mercury/Mariner OE: 87-17009A5, 87-17009A2, MP51090, MP41070-2, MP41070-1.
• 6-wire configuration accommodates push-to-choke systems used on many models.
• Color-matched wires simplify plug-in or splice connections during replacement.
• Not an OEM part but engineered to meet OEM fit and function standards.

How easy is installation and what tools are required?

Installation is straightforward for anyone comfortable with basic marine electrical work. The color-coded wires match factory colors to reduce guesswork; in many cases you’ll only need basic hand tools and wire connectors to swap the switch.

• Color-coded wiring for simple matching to the existing harness.
• Requires standard tools: screwdriver, wire strippers, and marine-grade connectors.
• Plug-and-play fit where the original connector matches, or splice-in where needed.
• Includes two keys so you have a spare ready on installation.

What materials and durability features are included?

The switch pairs brass electrical contacts with a non-conductive polyester housing to resist oxidation and prevent accidental shorts. These material choices extend service life in harsh saltwater and humid environments common to boating.

• Polyester housing provides abrasion and moisture resistance.
• Brass internals improve conductivity and reduce corrosion-related failure.
• Non-conductive exterior helps prevent short circuits.
• Designed for marine use with improved oxidation protection.

Who is this for? Boaters, marine mechanics, and DIY enthusiasts who need a reliable replacement ignition switch for compatible Mercury or Mariner outboard control boxes will benefit from this Tutor Auto unit. It’s especially useful when the original switch becomes stiff, intermittent, or fails to operate the choke—providing a cost-effective, OEM-compatible repair option with two keys and clear wiring for fast installation. The product includes a one-year warranty and customer support for troubleshooting and assistance.