Carburetor Set – Fits Mercury 2-Stroke 40-60 HP (Replaces 821854T4, 821854T5, 821854T6)
Carburetor Set – Fits Mercury 2-Stroke 40-60 HP (Replaces 821854T4, 821854T5, 821854T6) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Carburetor Set – Fits Mercury 2-Stroke 40-60 HP (Replaces 821854T4,...
Carburetor Set – Fits Mercury 2-Stroke 40-60 HP (Replaces 821854T4, 821854T5, 821854T6) is backordered and will ship as soon as it is back in stock.
Product Details
This complete TOP Center Bottom Carburetor Set is a direct-fit replacement assembly for 3-cylinder Mercury Marine 2-Stroke outboard engines from 40 HP to 60 HP, manufactured between 1999–2006.
It serves as a direct interchange for Mercury part numbers 821854T4, 821854T5, 821854T6 and their alternate versions, as well as complete Sierra aftermarket set 18-7386.
- Designed for direct, hassle-free installation using factory hardware.
- Compatible with all original factory fuel lines and throttle/choke linkages.
- Includes all three required carburetors: Top, Center, and Bottom.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury | 821854T4 / 821854A4 / 821854T19 | Top Carburetor |
| Mercury | 821854T5 / 821854A5 / 821854T20 | Center Carburetor |
| Mercury | 821854T6 / 821854A6 / 821854T21 | Bottom Carburetor |
| Sierra | 18-7386 | Complete Set (Top, Center & Bottom) |
Engine & Model Compatibility
Confirm your engine model and year range in the table below to ensure accurate fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 3-Cylinder | 40 | 2-Stroke | 1999–2006 | 821854T4 (Top), 821854T5 (Center), 821854T6 (Bottom) | |
| Mercury | 3-Cylinder | 45 | 2-Stroke | 1999–2006 | 821854T4 (Top), 821854T5 (Center), 821854T6 (Bottom) | Includes JET models |
| Mercury | 3-Cylinder | 50 | 2-Stroke | 1999–2006 | 821854T4 (Top), 821854T5 (Center), 821854T6 (Bottom) | |
| Mercury | 3-Cylinder | 55 | 2-Stroke | 1999–2006 | 821854T4 (Top), 821854T5 (Center), 821854T6 (Bottom) | |
| Mercury | 3-Cylinder | 60 | 2-Stroke | 1999–2006 | 821854T4 (Top), 821854T5 (Center), 821854T6 (Bottom) |
Technical Specs
- Product Type
- Complete Carburetor Set (3 carburetors)
- Installation
- Direct Replacement
- Fuel Type
- Gasoline
- Connection
- OEM Factory Linkage Compatible
- Housing Material
- Zinc Alloy
- Housing Color
- Silver/Metallic
- Fitting Type
- Factory Standard
- Thread Size
- Factory Standard
- Warranty
- 1 Year (Manufacturer's Defects)
- Other Technical Attributes
- Manufactured to OEM specifications, ISO9002 certified production
What’s in the Box
- 3 x Carburetor Assembly (Replaces Top, Center, and Bottom positions)
Installation Notes
- Disconnect the battery and secure any loose wires before starting.
- Turn off the fuel supply valve and safely disconnect the fuel line from the carburetors.
- Carefully label and disconnect all throttle linkages, choke linkages, and any vacuum or breather hoses.
- Remove the nuts or bolts securing the carburetor assembly to the intake manifold and remove the old set.
- Clean the manifold mounting surface and install the new carburetors with fresh gaskets.
- Reconnect all linkages and hoses to their correct positions, ensuring free movement.
- Reconnect the fuel line and turn on the fuel supply, checking thoroughly for any leaks.
- Reconnect the battery.
- Start the engine in a well-ventilated area. It may require fine-tuning of the idle mixture or speed screws for optimal performance.
Troubleshooting & FAQ
Will this set fit my specific Mercury motor?
This set is designed for the Mercury 3-cylinder 40-60 HP 2-stroke models listed in the Engine & Model Compatibility table. Please verify your model and year range before ordering.
Are these carburetors pre-adjusted?
These carburetors are preset at the factory to baseline specifications that work for most engines. However, due to variations in engine wear and atmospheric conditions, minor adjustments to the idle speed or air/fuel mixture screws may be necessary for optimal performance.
What are the signs my old carburetors need replacing?
Common symptoms of failing carburetors include difficulty starting, rough or erratic idling, engine stalling at low speeds, hesitation upon acceleration, black smoke from the exhaust, and visible fuel leaks from the carburetor body.
How do I distinguish the Top, Center, and Bottom carburetors?
The carburetors are often marked (e.g., with "TOP" or position numbers) on their housing. If not marked, compare them closely to your old units before removal; there are typically subtle differences in linkage arms or jetting. It is critical to install each carburetor in its correct position.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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