Quicksilver NGK Iridium Spark Plug Set 4-Pack (889246Q39)
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The Quicksilver 889246Q39 Spark Plug Set includes four NGK Laser Iridium spark plugs for Mercury applications that call for this exact part number. This plug is identified as NGK ILFR6GE / ILFR6G-E and is sold by Mercury as a genuine Quicksilver replacement. Mercury notes these plugs come pre-gapped to engine specification, but the gap should still be checked before installation.
Key Features
- Genuine Quicksilver / Mercury replacement spark plug set
- 4-pack for engines requiring four plugs
- NGK Laser Iridium design for durability and consistent ignition performance
- Mercury part number 889246Q39
- NGK plug identifier ILFR6GE / ILFR6G-E
Engine Compatibility
This set is commonly listed for certain Mercury Verado L4 applications, including 1.7L 135, 150, 175, and 200 HP models. Some sellers also associate the same plug family with additional Verado applications, but exact fitment should always be confirmed against the engine model and serial number before ordering.
Serial Number Fitment Notice
Please confirm compatibility by checking your Mercury engine serial number and owner’s manual before purchase. Mercury specifically advises using only the spark plug listed for your engine.
When This Part Needs Replacement
Replace spark plugs during scheduled tune-up service or when you notice hard starting, rough idle, misfiring, reduced fuel efficiency, or weak acceleration. One marine retailer specifically notes a 300-hour service interval recommendation for these NGK plugs on applicable Mercury engines.
Installation Notes
Always verify the plug gap before installation, even when the plugs are supplied pre-gapped. Install only the exact plug specified for your engine to help maintain proper performance and avoid ignition-related issues.
Alternate / Superseded Part Numbers
- NGK ILFR6GE / ILFR6G-E
- NGK stock number 4212
Cross-reference should still be verified by engine model and serial number before use.
Parts Desk Insight
For modern Mercury applications, using the exact spark plug matters more than many boat owners realize. Heat range, electrode design, and factory spec all affect idle quality, throttle response, and long-term ignition reliability, especially on supercharged or high-output four-stroke platforms. Mercury’s own guidance is to stick with the plug listed in the manual for the engine.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
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We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
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