Carburetor Assembly for Tohatsu and Nissan 9.9–18 HP Two-Stroke Outboards — Replaces 3G2-03100-0 and Sierra 18-7848
Carburetor Assembly for Tohatsu and Nissan 9.9–18 HP Two-Stroke Outboards — Replaces 3G2-03100-0 and Sierra 18-7848 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Carburetor Assembly for Tohatsu and Nissan 9.9–18 HP Two-Stroke Out...
Carburetor Assembly for Tohatsu and Nissan 9.9–18 HP Two-Stroke Outboards — Replaces 3G2-03100-0 and Sierra 18-7848 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket carburetor assembly is intended as a replacement for selected Tohatsu and Nissan 9.9 HP, 15 HP, and 18 HP two-stroke outboard applications. Listed model applications include Tohatsu M9.9D2, M15D2, and M18E2, along with corresponding Nissan NS9.9D2, NS15D2, and NS18E2 models.
The assembly is listed as a replacement for Tohatsu reference numbers 3G2-03100-0, 3G2-03100-1, 3G2-03100-2, 3G2-03100-3, 3G2-03100-4, and 3G2-03100-5, and for aftermarket reference Sierra 18-7848. Confirm the number on your original carburetor and verify the complete engine model before ordering.
- Replacement carburetor assembly for selected two-stroke outboard engines.
- Designed for direct installation at the original carburetor mounting location.
- Uses a mounting gasket to help provide a proper seal; a gasket is not listed as a separate included item.
- Intended to restore proper fuel metering when the original carburetor is worn, damaged, or no longer serviceable.
Part Number References
The following numbers are reference identifiers associated with this listing. They should be compared with the number and configuration of the carburetor being replaced.
| Brand | Part Number | Reference Type |
|---|---|---|
| Tohatsu | 3G2-03100-0 | OEM reference |
| Tohatsu | 3G2-03100-1 | Related or superseded reference |
| Tohatsu | 3G2-03100-2 | Related or superseded reference |
| Tohatsu | 3G2-03100-3 | Related or superseded reference |
| Tohatsu | 3G2-03100-4 | Related or superseded reference |
| Tohatsu | 3G2-03100-5 | Related or superseded reference |
| Sierra | 18-7848 | Aftermarket cross-reference |
Engine and Model Compatibility
The applications below are the listed model references for this carburetor. Model, horsepower, stroke type, and the number on the original carburetor must all match before installation.
| Brand | Model | Rated HP | Stroke | Listed Reference |
|---|---|---|---|---|
| Tohatsu | M9.9D2 | 9.9 HP | 2-Stroke | 3G2-03100 series |
| Tohatsu | M15D2 | 15 HP | 2-Stroke | 3G2-03100 series |
| Tohatsu | M18E2 | 18 HP | 2-Stroke | 3G2-03100 series |
| Nissan | NS9.9D2 | 9.9 HP | 2-Stroke | 3G2-03100 series |
| Nissan | NS15D2 | 15 HP | 2-Stroke | 3G2-03100 series |
| Nissan | NS18E2 | 18 HP | 2-Stroke | 3G2-03100 series |
Important: Compatibility can vary by model revision, production year, serial-number range, and carburetor configuration. If your engine identification plate or original carburetor shows a different model or part number, confirm fitment before purchase.
Technical Specifications
- Product Type
- Carburetor assembly
- Application
- Selected Tohatsu and Nissan 9.9–18 HP two-stroke outboards
- Fuel
- Gasoline
- Installation
- Direct replacement at the original mounting location
- Mounting
- Uses the engine's factory mounting points and a suitable gasket
- Finish
- Metallic or silver-colored housing
- Adjustment
- Inspection and possible idle or mixture adjustment may be required after installation
- Gasket
- Not listed as a separate included item; inspect and replace the gasket as required
- Warranty
- Refer to the applicable order and store warranty terms
What's in the Box
- 1 x Carburetor assembly
A replacement mounting gasket and any additional engine-specific hardware are not listed as included. Reuse hardware only if it is serviceable and obtain a suitable new gasket when required.
Installation Notes
- Turn the engine off, allow it to cool, and place it in a stable, well-ventilated work area.
- Shut off the fuel supply and disconnect the battery according to the engine manufacturer's safety procedure.
- Clean the area around the carburetor before disconnecting the fuel line to help prevent dirt from entering the fuel system.
- Disconnect the fuel line, throttle and choke linkages, and any other attached hoses or fittings.
- Remove the mounting fasteners and take off the original carburetor.
- Inspect the mounting surface and replace the gasket if it is damaged, compressed, or otherwise unsuitable.
- Install the replacement carburetor with the gasket correctly aligned. Tighten the fasteners evenly to the engine manufacturer's specification.
- Reconnect the linkages, fuel line, and any removed fittings. Confirm that the throttle and choke operate freely.
- Restore the fuel supply and check carefully for leaks before starting the engine.
- Start the engine in a safe area and check idle quality, throttle response, and fuel leakage. Adjust only as permitted by the engine service instructions.
Troubleshooting and FAQ
How do I confirm that this carburetor fits my engine?
Check the engine brand, exact model, horsepower, two-stroke configuration, and the number stamped or listed on the original carburetor. Compare all of those details with the compatibility table and reference numbers. Do not rely on horsepower alone.
Does the package include a gasket?
A gasket is not listed as a separate item in the package contents. Plan to inspect the existing gasket and install a suitable new gasket when required for a proper seal.
Will adjustment be needed after installation?
Possibly. Idle quality and mixture can be affected by engine condition, fuel quality, storage, altitude, and other factors. Follow the applicable service instructions and do not make adjustments beyond the manufacturer's specifications.
What symptoms can indicate a carburetor problem?
Common symptoms include hard starting, rough or unstable idle, stalling, poor acceleration, excessive fuel consumption, fuel leakage, or abnormal exhaust smoke. Other fuel-system or ignition faults can cause similar symptoms, so diagnose the engine before replacing parts.
Is this an OEM carburetor?
No. This listing is for an aftermarket replacement assembly intended for the listed applications and reference numbers. It is not sold as a genuine Tohatsu, Nissan, or Sierra-branded part.
How often should a marine carburetor be serviced?
Service needs depend on fuel quality, operating conditions, and storage practices. Use fresh fuel, follow the engine manufacturer's storage procedure, and clean or service the carburetor when contamination or performance symptoms occur.
What should I do if the part does not match my original?
Do not force installation or modify the mounting, linkage, or fuel connections. Compare the model and reference number again and contact support before installing the part.
Safety and Important Information
- Work only on a cool engine in a well-ventilated area away from sparks, flames, and other ignition sources.
- Gasoline is flammable. Clean spills promptly and dispose of fuel-contaminated materials safely.
- Verify the exact model, stroke type, serial range when applicable, and original carburetor reference before ordering.
- Check all fuel connections for leaks before operation and after the first test run.
- Professional installation is recommended when you are not familiar with outboard fuel-system service.
About Sea Sierra
- Marine Replacement Parts — Parts are selected for practical repair and maintenance applications.
- Application-Focused Listings — Compare engine identification details and reference numbers before ordering.
- Customer Support — Contact support with your engine model and original-part information if you need help confirming an application.
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