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Description
Ignition Key Switch – Fits Mercury/Mariner DFI, EFI & MPI Outboard Motors (Replaces 87-17009A5)Ignition Key Switch Fits Mercury Mariner DFI, EFI & MPI Outboard Motors (Replaces 87 17009A5) This panel mounted ignition key switch is a reliable replacement for Mercury and Mariner outboard motor control boxes requiring a 6 wire connection. It is designed for compatibility with a range of DFI (Direct Fuel Injection), EFI (Electronic Fuel Injection), and MPI (Multi Point Injection) engines. This unit is a direct replacement for Mercury part numbers
Ignition Key Switch – Fits Mercury/Mariner DFI, EFI & MPI Outboard Motors (Replaces 87-17009A5)
This panel-mounted ignition key switch is a reliable replacement for Mercury and Mariner outboard motor control boxes requiring a 6-wire connection. It is designed for compatibility with a range of DFI (Direct Fuel Injection), EFI (Electronic Fuel Injection), and MPI (Multi-Point Injection) engines.
This unit is a direct replacement for Mercury part numbers 87-17009A5 and 87-17009A2, as well as Sierra part numbers MP41070-2, MP41070-1, and MP41070.
- Installation Type: Panel Mount
- Connection: 6-Wire
- Package Includes: 1x Ignition Key Switch, 2x Keys
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury | 87-17009A5 |
| Mercury | 87-17009A2 |
| Sierra | MP41070-2 |
| Sierra | MP41070-1 |
| Sierra | MP41070 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Mercury/Mariner | DFI EFI MPI Outboard Motors | Various | Various | 87-17009A5 | Suits serial range: 0N001590+, 0G575500+ |
Technical Specifications
| Specification | Value |
|---|---|
| Product Type | Ignition Key Switch |
| Installation | Panel Mount |
| Fuel Type | Gasoline |
| Connection | 6-Wire |
| Housing Material | Polyester Anti-Corrosion Housing with Brass Contacts |
| Dimensions | 57 × 37 mm (2.3 × 1.5 in) |
| Weight | 117g (4.1 oz) approximate |
| Mounting Hole | 7/8" Thread Size |
| Operating Voltage | 12V DC |
| Current Rating | Ignition: 15 Amp @ 12V DC Solenoid: 30 Amp @ 12V DC Choke: 7 Amp @ 12V DC |
| Switch Positions | 3-Position (OFF - RUN - START) |
| For Panels Up To | 15.87 mm (5/8") thickness |
| Other Technical Attributes | Has return spring for 3 positions |
Package Contents
- 1 × Ignition Key Switch (87-17009A5)
- 2 × Ignition Keys
Installation Guide
- Safety First: Disconnect the boat's battery cables (negative first, then positive) to prevent electrical shorts.
- Access the Switch: Open or remove the control box panel to access the back of the old ignition switch.
- Label and Disconnect: Before disconnecting, label each wire to ensure correct placement on the new switch. Carefully unplug the 6-wire connector.
- Remove Old Switch: Unscrew the mounting nut on the front of the panel and remove the old ignition switch.
- Install New Switch: Insert the new ignition switch into the panel, orient it correctly, and tighten the mounting nut until snug. Do not overtighten.
- Reconnect Wires: Attach the 6-wire connector to the new switch, ensuring it is fully seated and secure.
- Test the System: Reconnect the battery (positive first, then negative) and test all switch positions (OFF, RUN, START) to confirm proper function before heading out on the water.
Troubleshooting & FAQ
Q: How do I confirm this ignition switch fits my specific Mercury engine?
A: This switch fits various Mercury/Mariner DFI, EFI, and MPI outboard motors. The best way to confirm is to match your existing part number to the ones listed in our cross-reference table (87-17009A5, 87-17009A2) or the Sierra equivalents. Also, ensure your system uses a 6-wire connection.
Q: What are the common signs that my ignition key switch is failing?
A: Common symptoms include difficulty turning the key, the engine not cranking or starting intermittently, the engine shutting off unexpectedly, or a loss of power to accessories when the key is in the 'RUN' position. Corrosion on the contacts can also be a visual indicator.
Q: Is this a direct replacement for the Sierra MP41070-2?
A: Yes, this ignition switch serves as a direct aftermarket replacement for Sierra part numbers MP41070-2, MP41070-1, and MP41070, along with the OEM Mercury numbers.
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
- Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
- Fast Global Shipping: Free delivery worldwide in 5–15 days.
- Direct from Manufacturer: Competitive pricing without compromising quality.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy