TOP Center Bottom Carburetor Set – Fits Mercury 2-Stroke 40-60 HP (Replaces 821854T4, 821854T5, 821854T6)
This is a complete aftermarket carburetor assembly set for Mercury Marine 2-Stroke 40, 45, 55, and 60 HP outboard engines (3-cylinder models, 1999–2006). It provides a reliable and cost-effective solution for restoring fuel system performance.
This set is a direct replacement for Mercury OEM part numbers 821854T4 (Top), 821854T5 (Center), and 821854T6 (Bottom), as well as their predecessors and equivalents.
- Includes a full set of three carburetors (Top, Center, Bottom).
- Designed for gasoline fuel types.
- Engineered for direct-fit installation using factory linkages.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Position |
Notes |
Mercury |
821854T4 / 821854A4 / 821854T19 |
Top |
|
Mercury |
821854T5 / 821854A5 / 821854T20 |
Center |
|
Mercury |
821854T6 / 821854A6 / 821854T21 |
Bottom |
|
Sierra |
18-7386 |
Complete Set |
Equivalent to the full set of 3 carburetors. |
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 |
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 |
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 Specifications
Specification |
Value |
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 |
Package Contents
- 3 x Carburetor Assembly (Replaces Top, Center, and Bottom)
Explosion Diagram
Installation Guide
-
Safety First: Disconnect the battery and ensure the engine is off and cool. Shut off the fuel supply.
-
Access the Carburetors: Remove the engine cowling or any covers to gain access to the carburetor bank.
-
Document Connections: Before disconnecting, take photos of the fuel lines, throttle linkages, and any electrical connections to ensure correct reassembly.
-
Disconnect Linkages: Carefully detach the throttle and choke linkages from the old carburetors.
-
Disconnect Fuel Lines: Disconnect the fuel inlet and any primer lines. Have a rag ready to catch any spilled fuel.
-
Remove Old Carburetors: Unbolt and remove the complete carburetor assembly from the intake manifold.
-
Install New Set: Mount the new carburetor set onto the intake manifold, ensuring it is seated correctly. Tighten the mounting bolts to the manufacturer's specified torque.
-
Reconnect Lines: Re-attach the fuel lines to the new carburetors.
-
Reconnect Linkages: Re-attach the throttle and choke linkages. Check for smooth, unrestricted movement.
-
Final Checks: Turn the fuel supply back on and check thoroughly for any fuel leaks. Once confirmed leak-free, reconnect the battery.
-
Test Engine: Start the engine in a well-ventilated area. Check for smooth idling and throttle response.
-
Adjust if Necessary: Make any necessary idle or air/fuel mixture adjustments according to your engine's service manual for optimal performance.
Troubleshooting & FAQ
Q: How do I confirm this set fits my specific Mercury outboard?
A: This set is designed for 3-cylinder Mercury 40-60 HP models from 1999-2006. The best way to confirm is to match your existing carburetor part numbers with those listed in our Part Number Cross-Reference table. You can also verify your engine's model and year in the Compatible Engine Models list.
Q: Are gaskets or installation hardware included with this carburetor set?
A: The package contains the three carburetor assemblies as shown. Gaskets or additional installation hardware are not specified as included. We recommend purchasing a separate gasket kit to ensure a proper, leak-free seal during installation.
Q: What are common signs that my old carburetors need replacing?
A: Common symptoms include difficulty starting, rough idling or stalling at low speeds, poor or hesitant acceleration, and a noticeable increase in fuel consumption. Visible fuel leaks or corrosion on the carburetor body are also clear indicators that a replacement is needed.
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.