812647T1 Carburetor for Mercury Mariner | JLM Marine

Carburetor for Mercury Mariner 2-Stroke 4HP 5HP Outboard Engines

This high-quality aftermarket carburetor is designed to fit Mercury Mariner 2-stroke outboard engines rated at 4HP and 5HP. Engineered to meet OEM specifications, this carburetor ensures reliable fuel delivery and optimal engine performance for your outboard motor.

This carburetor directly replaces OEM part numbers 812647T1, 3303-812647T1, and 3303-812648T, providing a cost-effective alternative to factory parts without sacrificing quality or reliability.

• Complete carburetor assembly ready for installation
• Compatible with 2-stroke gasoline engines
• Precision-manufactured for accurate fuel-air mixture

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

Technical Specifications

Package Contents

Your purchase includes:

• 1 x Outboard Engine Carburetor

Installation Guide

1. Disconnect the fuel line from the old carburetor and ensure the engine is completely cool before beginning work.
2. Remove the engine cover to access the carburetor assembly. Take note of all linkage positions and orientations.
3. Disconnect the throttle and choke linkages from the old carburetor carefully to avoid bending or damaging them.
4. Unbolt the old carburetor from the intake manifold using the appropriate wrench or socket. Keep all mounting hardware for reuse.
5. Clean the mounting surface on the intake manifold thoroughly, removing any old gasket material or debris.
6. Install the new gasket (if included or using a new one) on the intake manifold surface to ensure a proper seal.
7. Position the new carburetor onto the intake manifold and hand-tighten the mounting bolts initially.
8. Torque the mounting bolts to manufacturer specifications in a criss-cross pattern to ensure even seating.
9. Reconnect the throttle and choke linkages in their original positions, ensuring smooth operation without binding.
10. Attach the fuel line securely to the carburetor inlet and check for proper connection.
11. Prime the fuel system by squeezing the primer bulb until firm, then check for any fuel leaks around connections.
12. Start the engine and adjust idle settings as needed for smooth operation. Reinstall the engine cover once testing is complete.

Troubleshooting & FAQ

Q: How do I confirm this carburetor fits my Mercury Mariner engine?
A: Verify your engine is a 2-stroke 4HP or 5HP Mercury Mariner outboard. Cross-reference your existing carburetor's part number with 812647T1, 3303-812647T1, or 3303-812648T. You can also use the Mercury serial number guide and parts diagrams linked above to confirm compatibility.

Q: What are the signs that my carburetor needs replacement?
A: Common symptoms include difficulty starting, rough idling, poor acceleration, black smoke from the exhaust, excessive fuel consumption, or engine stalling. If cleaning the carburetor doesn't resolve these issues, replacement is recommended.

Q: How often should I replace or service my carburetor?
A: Carburetors don't have a fixed replacement interval. Regular cleaning and maintenance after every 50-100 hours of operation can extend lifespan. Replace when cleaning no longer restores performance or if internal components are damaged or corroded.

Q: Will this work exactly like my original Mercury carburetor?
A: Yes, this aftermarket carburetor is manufactured to OEM specifications and designed to deliver equivalent performance. It uses comparable-grade materials and is tested to ensure proper fuel delivery and engine operation.

Q: Do I need to adjust the carburetor after installation?
A: Minor idle and mixture adjustments may be necessary after installation to optimize performance for your specific engine. Refer to your engine's service manual for proper adjustment procedures.

Q: Is this an OEM part or 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.