Carburetor Set (3 Pack) – Fits Mercury Mariner 40HP 45HP 55HP 60HP 2-Stroke 3-Cylinder (Replaces 821854T4, 821854T5, 821854T6)

Product Details

This Carburetor Set (3 Pack) is engineered for Mercury Mariner 40HP, 45HP, 55HP, and 60HP 2-stroke 3-cylinder outboard engines. Designed as a direct-fit replacement, this aftermarket carburetor kit restores fuel delivery and throttle response across all three cylinders.

Replaces OEM part numbers 821854T4, 821854T5, and 821854T6, offering cross-compatibility with original Mercury Mariner components.

• Complete 3-carburetor assembly for synchronized fuel distribution
• Compatible with standard marine gasoline and ethanol-blended fuels
• Precision-calibrated for 2-stroke 3-cylinder Mercury Mariner engines

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Application

Mercury Mariner 2-Stroke 3-Cylinder Outboards

HP Range

40HP / 45HP / 55HP / 60HP

Carburetor Count

3 Units (Complete Set)

Fuel Type

Marine Gasoline (Ethanol-Compatible)

Installation Type

Direct OEM Replacement

What's in the Box

• 3 × Carburetor

Installation Notes

1. Disconnect the battery and turn off the fuel supply before beginning work.
2. Remove the engine cowling and locate the existing carburetor assembly on the intake manifold.
3. Disconnect the fuel lines, throttle linkage, and choke cables from each carburetor.
4. Remove the mounting nuts or bolts securing the carburetors to the intake manifold.
5. Carefully lift away the old carburetor set, noting the orientation of gaskets and linkages.
6. Inspect intake manifold surfaces and replace gaskets if worn or damaged.
7. Position the new carburetors onto the manifold, aligning mounting holes and ensuring gaskets sit flush.
8. Torque mounting fasteners evenly to manufacturer specifications to prevent air leaks.
9. Reconnect throttle linkage, choke cables, and fuel lines in the reverse order of removal.
10. Verify all connections are secure and fuel lines are properly clamped.
11. Reconnect the battery, turn on the fuel supply, and prime the system.
12. Start the engine and adjust idle mixture screws as needed for smooth operation across all cylinders.

Troubleshooting & FAQ

How do I know if my carburetors need replacement?

Common signs include rough idling, poor acceleration, difficulty starting, black smoke from the exhaust, or uneven RPM across cylinders. Fuel leaks or visible corrosion around carburetor bodies also indicate replacement is needed.

Will this set work on 4-stroke Mercury engines?

No, this carburetor set is designed exclusively for 2-stroke 3-cylinder Mercury Mariner engines rated at 40HP, 45HP, 55HP, and 60HP. It is not compatible with 4-stroke or 2-cylinder models.

Do I need to synchronize the carburetors after installation?

Yes, after installing the carburetor set, you should synchronize throttle response and idle mixture across all three cylinders. Use a tachometer and follow your engine's service manual for proper adjustment procedures.

Are gaskets and hardware included?

This package includes three carburetors only. Mounting gaskets, bolts, fuel line clamps, and throttle linkage hardware are not included and should be sourced separately or reused if in good condition.

Can I use this with ethanol-blended fuel?

Yes, these carburetors are compatible with standard marine gasoline and ethanol-blended fuels (E10). For optimal performance and longevity, use fresh fuel and add a fuel stabilizer if the engine will sit idle for extended periods.

What is the difference between OEM and aftermarket carburetors?

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.

How fast will my order ship and what does it cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

What warranty and return options are available?

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.

How often should carburetors be replaced or serviced?

Carburetors should be inspected annually or after every 100 hours of operation. Replace them if you notice persistent tuning issues, internal corrosion, or damaged internal components that cannot be cleaned or rebuilt.

Safety & Important Info

• Verify images/specifications against 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.