SKU: 99137878108

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

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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

  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

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Our pitt LOVES this toy. The rubber is reeeaally tough. It’s well designed because it’s a slippery surface. You can tell from the video there’s a lot of squeaking from him trying to get a good grip. He found a pretty good spot to hook his upper teeth into the crevasse, but his bottom teeth kept slipping. As a side note, I wouldn’t leave any toy home alone with him that’s about 3 inches or smaller because dogs can choke on it, but that doesn’t make this any toy or company any less amazing. For toys I would leave home with a power chewer, take a look at that 4inch red ball made by this same company. He hasn’t made a dent in that thing and you can put treats in it. :)
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Maria M.
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My dog lives these!
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Reviewed in the United States on April 23, 2026
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Shorty & Lily's Mom
Boise, US
★★★★★ 5
Takes a beating - looks like new!
Color: Blue/Medium, Size: Blue
EDITED AGAIN, 12/28/22: My boy still has his original blue one of these and the yellow one from way back. He's received a couple more over the years which he's managed to sneak out of the house and lose - evidently neighbor dogs or perhaps foxes, etc love them, too, and carry them off?! At any rate, he'd managed to get himself back to his original two, so I bought him a late Christmas present of a new yellow bone. He just opened the package (with help, of course - he's smart, but lacks the necessary opposing thumbs to do it on his own) and he was ecstatic! He reached into the mailing envelope, grabbed it, gave it a couple of triumphant tosses then ran for his bed, pulled a blanket in, and has been chewing, fighting with, burying in the blanket and "discovering" it for about a half hour now! I don't know what the attraction is, but he still loves these things and they're still lasting! The only other toys that have lasted more than a day are Nylabones (because he won't even look at them, let alone touch them) and a set of interlocked skinny rubber rings that he's not at all interested in, but if I ask about them, he'll move them around the room for a couple of days to make me feel better! LOL EDITED TO ADD 2022: Here I am, back 5 1/2 years later to say my dog STILL has this bone and makes use of it a couple of times a week. And he still loves it and sleeps with it. He has gone through a couple of the smaller version (yellow instead of blue) over this time frame because those get constant use. But that’s amazing in itself!! These are still the only toy I would call indestructible. Great toy! I have a dachshund who destroys toys in record time. I can hear the amused chuckles now, but anyone who has seen him in action (including rottie, pit bull and Doberman owners) is in awe. He is very methodical and relentless - the mad genius of dog toy torture! Small and quiet but utterly ruthless. Anyway...my boy has been working on this since the beginning of October and the thing looks like new! I think you can see one tooth mark, otherwise it looks untouched! This is a dog who can reduce Kongs and other rubber toys to a pile of chunks in minutes. But he also LOVES it - carries it around, brings it into his bed at night to sleep, and when his doxie brother (who is far too dignified to do dog toys) doesn't feel well, it is offered up as a "feel better" snuggly...for about 2 minutes. But it's the thought that counts, right? I don't know what makes this so attractive to my mini-Jaws and so long-lasting, but it works!
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Reviewed in the United States on February 3, 2017
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Michael & Challice R.
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★★★★★ 5
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Color: Blue/Medium, Size: Blue
Almost not destructible! My dogs chew through 99% of the toys we purchase, but never this one! The medium size is good for our Doberman with jaws of steel!
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