Carburetor for Mercury Mariner 4–5 HP 2-Stroke Outboards – Replaces 3303-812647T1, 812648T
Carburetor for Mercury Mariner 4–5 HP 2-Stroke Outboards – Replaces 3303-812647T1, 812648T is backordered and will ship as soon as it is back in stock.
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Carburetor for Mercury Mariner 4–5 HP 2-Stroke Outboards – Replaces...
Carburetor for Mercury Mariner 4–5 HP 2-Stroke Outboards – Replaces 3303-812647T1, 812648T is backordered and will ship as soon as it is back in stock.
Product Details
This is a replacement carburetor for Mercury Mariner 4–5 HP 2-stroke outboard engines. It is supplied as a single carburetor and is intended for applications using the matching original carburetor and mounting arrangement.
The company catalog identifies this product with Mercury reference numbers 3303-812647T1 and 812648T. Marine parts catalog records also list the related reference 3303-812648T as a carburetor for selected Mercury 4 HP and 5 HP 2-stroke applications.
- Replacement carburetor for selected Mercury and Mariner 4–5 HP 2-stroke outboards.
- Single carburetor assembly; this is not a multi-part kit.
- Use the original carburetor, engine model, horsepower, stroke, and serial number to confirm compatibility before ordering.
Part Number Matrix
Use the following manufacturer and catalog references when comparing your original component. Number listings are reference identifiers and should be confirmed against the complete engine application.
| Brand | Reference Number | Application Note |
|---|---|---|
| Mercury | 3303-812647T1 | Company-listed carburetor reference |
| Mercury | 812648T | Company-listed carburetor reference |
| Mercury | 3303-812648T | Catalog-listed carburetor reference for selected 4 HP and 5 HP applications |
Engine Compatibility
Catalog records associate reference 3303-812648T with selected Mercury 4 HP and 5 HP 2-stroke outboards in the serial-number ranges below. Keep the horsepower, stroke, model, and serial range together when checking fitment.
| Brand | Rated HP | Stroke | Serial Number Range | Catalog Reference |
|---|---|---|---|---|
| Mercury | 4 HP | 2-Stroke | 0G710613 through 0T894438 | 3303-812648T |
| Mercury | 5 HP | 2-Stroke | 0G710613 through 0T894438 | 3303-812648T |
| Mercury | 4 HP | 2-Stroke | 0T894439 and up | 3303-812648T |
| Mercury | 5 HP | 2-Stroke | 0T894439 and up | 3303-812648T |
| Mercury | 4 HP | 2-Stroke | 0P017000 through 0P400999 | 3303-812648T |
| Mercury | 4 HP | 2-Stroke | 0P401000 and up | 3303-812648T |
For Mariner applications, compare the engine nameplate and serial number with the original carburetor and the seller’s fitment information. Do not rely on horsepower alone, because serial-number breaks can change the correct carburetor.
Technical Specifications
- Product Type
- Carburetor
- Product Configuration
- Single replacement component, not a kit
- Brand Application
- Mercury Mariner
- Engine Application
- Selected 4–5 HP 2-stroke outboards
- Fuel System
- Carbureted 2-stroke outboard fuel system
- Company-Listed References
- 3303-812647T1 and 812648T
- Additional Catalog Reference
- 3303-812648T
- Fitment Requirement
- Match the original carburetor, engine model, horsepower, stroke, and serial number
What's in the Box
- 1 x Carburetor
Gaskets, hoses, linkages, mounting hardware, and other accessories are not listed as included unless specifically shown or stated with the product.
Installation Notes
- Turn the engine off, allow it to cool, disconnect the battery where applicable, and close or disconnect the fuel supply.
- Remove the engine cowling and photograph the existing throttle, choke, fuel-line, and linkage connections before disassembly.
- Disconnect the fuel line and any throttle or choke linkages from the original carburetor.
- Remove the retaining hardware and old carburetor. Protect the intake opening from dirt and debris.
- Inspect the mating surface and install the replacement carburetor with the correct gasket or sealing components for your engine.
- Reconnect the fuel line and all linkages in their original positions, then tighten the mounting hardware evenly.
- Check for fuel leaks before starting the engine. Prime the fuel system as required by the engine manufacturer.
- Start and test the engine in a safe, well-ventilated area. Adjust idle or mixture settings only according to the applicable service procedure.
Troubleshooting & FAQ
How do I confirm that this carburetor fits my engine?
Compare your original carburetor and its reference number with the numbers listed above, then verify the engine brand, model, horsepower, 2-stroke configuration, and serial-number range. Do not confirm fitment from horsepower alone.
Does this listing include a complete carburetor kit?
No. The company record identifies this product as a single carburetor rather than a kit. Additional gaskets, hoses, linkages, and mounting hardware are not included unless separately stated.
Will the carburetor require adjustment after installation?
Adjustment requirements depend on the engine and its service specifications. After installation, check for leaks and follow the applicable manufacturer procedure for starting, idle speed, and mixture adjustment.
What symptoms can indicate a carburetor problem?
Hard starting, rough idle, stalling, hesitation, surging, poor acceleration, or fuel leakage can be associated with carburetor issues. These symptoms can also result from fuel restrictions, ignition faults, air leaks, or incorrect adjustment, so inspect the complete fuel and ignition systems before replacing parts.
Can I clean the original carburetor instead of replacing it?
Cleaning may help when the problem is caused by varnish or blocked passages. It may not correct worn, damaged, corroded, or distorted components. Compare the condition of the original carburetor with the replacement before deciding which repair is appropriate.
What should I do before storing the outboard?
Follow the engine manufacturer's storage procedure. Use fresh fuel, stabilize the fuel when appropriate, and protect the fuel system from contamination and moisture during storage.
Is this an OEM Mercury component?
This listing is for a replacement carburetor. The listed Mercury reference numbers are provided for identification and fitment comparison; the product should not be treated as a genuine OEM component unless the listing specifically states otherwise.
Safety & Important Information
- Verify the carburetor appearance, connections, reference number, engine model, horsepower, stroke, and serial range before ordering.
- Fuel is flammable. Work in a well-ventilated area away from flames, sparks, and other ignition sources.
- Disconnect the fuel supply before removing the carburetor and check carefully for leaks after installation.
- Use the correct gasket and follow the engine manufacturer's service instructions and torque specifications.
- Professional installation is recommended if you are not familiar with marine fuel systems.
About Sea Sierra
- Marine Replacement Parts — We provide replacement components for common outboard repair applications.
- Fitment-Focused Listings — Reference numbers and application details are provided to help you compare the replacement with your original part.
- Practical Support — When checking fitment, have your engine brand, model, horsepower, stroke, and serial number available.
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