Ignition Key Switch – Fits Mercury/Mariner DFI, EFI & MPI Outboard Motors (Replaces 87-17009A5)
SKU: 99137878108

Ignition Key Switch – Fits Mercury/Mariner DFI, EFI & MPI Outboard Motors (Replaces 87-17009A5)

Sale price$19.79 Regular price$21.99
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 6 - Jul 11

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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

  1. Safety First: Disconnect the boat's battery cables (negative first, then positive) to prevent electrical shorts.
  2. Access the Switch: Open or remove the control box panel to access the back of the old ignition switch.
  3. Label and Disconnect: Before disconnecting, label each wire to ensure correct placement on the new switch. Carefully unplug the 6-wire connector.
  4. Remove Old Switch: Unscrew the mounting nut on the front of the panel and remove the old ignition switch.
  5. Install New Switch: Insert the new ignition switch into the panel, orient it correctly, and tighten the mounting nut until snug. Do not overtighten.
  6. Reconnect Wires: Attach the 6-wire connector to the new switch, ensuring it is fully seated and secure.
  7. 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:
  1. 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
SKU: 99137878108

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.3 ★★★★★
Based on 1713 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
A
Verified Purchase
Amber Bennett
West Palm Beach, US
★★★★★ 5
Best for a blow out!
Size: Size 5, Unit Count: 58
We loved pampers for months then my baby turned 7 months and started having blow outs bc he was so mobile. Huggies little movers fix that problem! Nice and thick, completely leak proof by the legs and up the back, nice and soft!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 17, 2026
P
Verified Purchase
Paula S.
Charlottesville, US
★★★★★ 4
Great diapers, just a couple small issues
Size: Size 4, Unit Count: 150
Size 4 have been super reliable for my baby. They fit well, don’t sag, and handle active movement without leaking. The absorbency is great for daytime and short naps. My only minor complaint is that they can be a bit pricey compared to other brands, and occasionally the tabs feel a little stiff. Still, otherwise it’s a dependable diaper that I would definitely recommend
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 14, 2025
B
Verified Purchase
Brianna
Chelsea, US
★★★★★ 5
Reliable Fit for Bigger ToddlersI’m
Size: Size 7, Unit Count: 88
These diapers are great quality and hold up really well for active toddlers. My son has always had thicker legs, and these have suited him really well without being too tight or causing irritation. He just turned two and is already in a size 7 (almost an 8), so sizing up has definitely been helpful for comfort and better coverage for US. The absorbency is consistent, and they stay in place—overall a very dependable choice.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 26, 2026
A
Verified Purchase
Amazon Customer
Alexandria, US
★★★★★ 5
Great water flosser
Color: Pink+purple
Got it for my 10 year old with braces and it works great! She even takes it to sleepovers! It’s so portable and the travel safe design is great. It’s a very reasonable price as well. Would highly recommend
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 2, 2025
V
Verified Purchase
Valid buyer
Chelsea, US
★★★★★ 5
Good buy
Color: Pink+purple
Kids love it. Still works great
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 2, 2026

recommand products