ACDelco 41-993 Iridium Spark Plug — 4-Pack | MerCruiser GM V6 Marine Engines
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You have 30 days to request a return. All sale items are final sale.
ACDelco Iridium Professional Spark Plugs for MerCruiser & GM V6 Marine Engines
The ACDelco 41-993 Iridium Professional spark plug is the OEM-specified iridium plug for MerCruiser and GM V6-based marine engines. The fine-wire iridium electrode delivers a more focused spark for improved combustion efficiency, smoother idle, and quicker throttle response. Sold as a 4-pack — a complete set for a 4-cylinder engine or half a set for a V8.
Compatible Applications
- MerCruiser GM V6 marine engines requiring ACDelco 41-993 spark plug
- GM V6-based marine engines — MerCruiser, Crusader, and Indmar applications (verify OEM plug number before ordering)
Key Features
- Fine-wire iridium center electrode for precise, consistent spark
- OEM-specified plug for MerCruiser GM V6 applications
- Reduced ignition system voltage demand — extends the life of coils, wires, and ignition components
- Improved cold-start performance and throttle response
- Long-life iridium design for extended service intervals
- Sold as a 4-pack (standard pack)
Parts Desk Insights
The ACDelco 41-993 is the correct iridium plug for MerCruiser GM V6 marine engines — it is a different specification than the ACDelco 411104 and ACDelco 411014, which cover different GM marine engine configurations. Using the wrong plug number can cause misfires, fouling, or ignition damage, so always cross-reference your engine’s OEM part number before ordering. The iridium upgrade is particularly worthwhile on marine engines because the lower voltage demand reduces wear on coils and wires — components that are more expensive and harder to service on the water. For the OEM Mercury Quicksilver equivalent, see the Mercury MerCruiser Quicksilver Spark Plug (AC 41-993).
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
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.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.