Carburetor Assembly – Fits Mercury Mariner 40HP, 45HP, 55HP & 60HP 2-Stroke 3-Cylinder Outboards

Product Details

This carburetor assembly is designed for specified Mercury Mariner 40HP, 45HP, 55HP, and 60HP 2-stroke, 3-cylinder outboard applications. It is intended as an aftermarket replacement for the engine's carburetor assembly and supports proper fuel metering when the original component is worn, damaged, or contaminated.

The assembly is associated with Mercury reference numbers 821854T4, 821854T5, and 821854T6. Confirm the exact engine model, year, serial range, original carburetor configuration, and physical details before ordering.

• Aftermarket carburetor assembly for selected Mercury Mariner outboards
• Application-specific design for 2-stroke, 3-cylinder engines
• Suitable for replacement of a matching original carburetor assembly
• Verify the original component and engine identification before installation

Part Number References

The following manufacturer reference numbers are associated with this application. They are provided for identification and cross-reference purposes; number placement and carburetor configuration should be checked against the original part.

Engine & Model Compatibility

Compatibility is limited to the stated engine family and configuration. Confirm the complete model designation, year, serial range, mounting arrangement, and carburetor position before purchase.

Technical Specs

Application

Mercury Mariner 2-stroke, 3-cylinder outboards

Rated Applications

40HP / 45HP / 55HP / 60HP

Product Type

Single aftermarket carburetor assembly

Stroke

2-Stroke

Engine Configuration

3-Cylinder

Reference Numbers

821854T4 / 821854T5 / 821854T6

What's in the Box

• 1 × Carburetor assembly

Gaskets, mounting hardware, fuel-line clamps, cables, linkages, and other installation parts are not confirmed as included unless specifically shown or stated with the product.

Installation Notes

1. Disconnect the battery and shut off the fuel supply before beginning work.
2. Remove the engine cowling and identify the carburetor assembly on the intake side of the engine.
3. Record the routing and orientation of the fuel lines, throttle linkage, choke components, and any attached fittings.
4. Disconnect the fuel lines and control linkages, taking care to prevent fuel spills and contamination.
5. Remove the fasteners securing the original carburetor assembly and carefully lift it away.
6. Inspect the intake and mounting surfaces. Replace damaged or deteriorated gaskets before installation.
7. Position the replacement assembly with the correct orientation and secure it evenly with the appropriate fasteners.
8. Reconnect the fuel lines, throttle linkage, choke components, and any fittings in their original positions.
9. Check that the throttle moves freely and that all fuel connections are secure before starting the engine.
10. Prime the fuel system, inspect for leaks, and follow the engine service manual for idle and synchronization adjustments.
11. Run the engine in accordance with the service manual and verify stable idle and throttle response before normal use.

Troubleshooting & FAQ

How do I know if my carburetor needs replacement?

Possible symptoms include hard starting, rough idle, poor acceleration, inconsistent engine speed, fuel leakage, or visible corrosion and damage. These symptoms can also result from fuel-system, ignition, or adjustment problems, so diagnose the engine before replacing the carburetor.

Will this assembly work on 4-stroke Mercury engines?

No. The listed application is for Mercury Mariner 2-stroke, 3-cylinder engines rated at 40HP, 45HP, 55HP, and 60HP. Do not use it for 4-stroke engines or configurations that do not match the stated application.

Do I need to adjust the carburetor after installation?

Adjustment or synchronization may be required after installation. Follow the service manual for the exact engine and use the correct procedures and specifications for idle, throttle linkage, and fuel mixture settings.

Are gaskets and hardware included?

The confirmed package is one carburetor assembly. Gaskets, bolts, fuel-line clamps, linkage hardware, and other accessories are not confirmed as included and should be checked before installation.

Is this an OEM part?

No. This listing is for an aftermarket replacement carburetor assembly. The Mercury numbers shown on this page are application reference numbers and should be compared with the original component before ordering.

Can I install it without checking the engine serial number?

Do not rely on horsepower alone. Mercury and Mariner applications can vary by model, year, serial range, carburetor position, and linkage arrangement. Compare the original carburetor and confirm the full engine identification before purchase.

How often should a carburetor be serviced?

Service requirements depend on fuel quality, storage conditions, operating hours, and the engine manufacturer's maintenance schedule. Inspect the fuel system regularly and service the carburetor if contamination, varnish, leakage, corrosion, or performance problems are found.

Safety & Important Info

• Verify the engine brand, model, year, serial range, horsepower, stroke, cylinder count, and original carburetor configuration before ordering.
• Compare the mounting points, linkage arrangement, fuel connections, and physical appearance with the original component.
• This is an aftermarket replacement, not an OEM component.
• Work in a well-ventilated area away from ignition sources and clean up fuel spills immediately.
• Professional installation is recommended when carburetor adjustment or synchronization is required.

About Sea Sierra

• Marine Replacement Parts — We provide aftermarket components for selected marine applications.
• Application-Focused Listings — Product references and fitment details are provided to help customers compare replacement parts.
• Installation Support — Always use the engine manufacturer's service information for installation, adjustment, and maintenance procedures.