Mercury MerCruiser Quicksilver 3-Inch Riser Extension Kit 864929A3 | Standard Cooling Dry Joint
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Mercury / Quicksilver OEM 3-Inch Riser Extension Kit — Part No. 864929A3
| Part Number | 864929A3 |
|---|---|
| Brand | Mercury Marine / Quicksilver |
| Product Type | Exhaust Riser Extension Kit |
| Extension Height | 3 in. / 76 mm |
| Kit Contents | 2 riser extensions (1 kit services one engine) |
| Exhaust System | Dry-Joint |
| Cooling Type | Standard / Raw-Water Cooling |
| UPC / GTIN | 745061564657 |
| Supersedes / Related | 864929A1 (earlier reference) |
About This Kit
The 864929A3 is a genuine Mercury Marine / Quicksilver OEM exhaust riser extension kit that raises the exhaust elbow connection by 3 inches (76 mm) on MerCruiser dry-joint exhaust systems with standard (raw-water) cooling. Each kit contains two riser extensions, providing everything needed to service one complete engine installation. Proper riser height is critical in marine applications — adequate separation between the exhaust outlet and waterline helps prevent water from entering the exhaust system.
Important distinction: The A3 suffix identifies this as the standard / raw-water cooling version. The companion kit 864929A4 is for closed-cooling applications. Both use 3-inch extensions but they are not interchangeable — confirm your cooling system type before ordering.
Compatible Applications
Confirm the engine serial number, cooling-system type, and dry-joint exhaust configuration before ordering.
- 2004–2016 MerCruiser sterndrive V6 & V8 — 305 CID / 5.0L, 350 CID / 5.7L, 377 CID / 6.2L (non-EC engines, SN 0W310000 and up)
- 2002–2016 MerCruiser inboard V8 — 350 CID / 5.7L, 377 CID / 6.2L (non-EC engines, SN 0M390000 and up)
- Standard / raw-water cooled dry-joint exhaust manifold configurations only
When This Kit Is Needed
- Riser spacers are corroded, pitted, or cracked
- Exhaust system rebuild requiring replacement of original 3-inch spacers
- Exhaust outlet height needs to be restored to factory specification
- New boat installation requiring additional riser height
- Water intrusion suspected due to insufficient exhaust-to-waterline separation
Installation Notes
- Verify the engine uses a dry-joint exhaust manifold — do not install on wet-joint systems
- Confirm standard / raw-water cooling — closed-cooling engines require 864929A4
- Inspect both exhaust manifolds and elbows for corrosion or erosion before reassembly
- Replace dry-joint gaskets during reassembly — gasket selection depends on cooling configuration (restrictor 864850A02, block-off 864549A02, or full-flow 864547A02)
- Check all mating surfaces for pitting before torquing fasteners
- Verify exhaust hose and elbow alignment after the 3-inch extension is installed
- Follow the applicable MerCruiser service manual for torque specs and gasket selection
Kit Contents
- 2 × 3-inch (76 mm) exhaust riser extensions
- One kit services one complete engine
Related & Alternate Part Numbers
- 864929A1 — earlier related reference (superseded by A3)
- 864929A4 — 3 in. riser extension kit, closed-cooling version
- 865995A01 — 1.7 in. riser extension kit, standard cooling
- 865996A01 — 1.7 in. riser extension kit, closed cooling
- 864850A02 — restrictor gasket for riser / cooling circuit
- 864549A02 — block-off gasket
- 864547A02 — full-flow gasket
- Sierra 18-1847K — aftermarket 3 in. dry-joint standard-cooling spacer kit (cross-reference)
Related Products
- Sierra Exhaust Manifold — Dry Joint — 47-1842 — dry-joint exhaust manifold for MerCruiser applications
Parts Desk Insights
The single most common ordering mistake on this kit is confusing standard cooling (A3) with closed cooling (A4). Both are 3-inch dry-joint kits and look identical, but they are engineered for different cooling circuits. Check your engine's cooling system type first — if your engine uses a heat exchanger (fresh-water cooled), you need the A4; if it circulates raw lake or sea water directly through the engine, you need the A3. When in doubt, your engine's serial number and the parts diagram will confirm which version applies.
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.