3F0-03100 Carburetor for Mercury Tohatsu Nissan M3.5A2 M3.5B2 NS3.5A2 NS3.5B2 | JLM Marine

3F0-03100 Carburetor for Mercury Tohatsu Nissan M3.5A2 M3.5B2 NS3.5A2 NS3.5B2

This carburetor assembly is engineered for Mercury Mariner 2-stroke outboards (1 cylinder, 2HP–3.3HP) as well as Tohatsu and Nissan 3.5HP 2-stroke models including M3.5A2, M3.5B2, NS3.5A2, and NS3.5B2. It provides reliable fuel delivery for small displacement outboards across multiple model years.

This carburetor directly replaces OEM part numbers 3F0-03100, 3F0-03100-1, 3F0-03100-2, 3F0-03100-4, 3D5-03100, 3D5-03100-2, and 3303-815070, ensuring broad compatibility across Tohatsu, Nissan, Mercury, Johnson, and Evinrude OMC applications.

• Fits 2-stroke outboards from 2HP to 3.5HP
• Compatible with Mercury Mariner 1-cylinder models and Tohatsu/Nissan M/NS 3.5 series
• Complete carburetor assembly ready for installation

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

• 1 × Carburetor Assembly (Complete)

Installation Guide

1. Disconnect the fuel line from the old carburetor and place a container beneath to catch any residual fuel. Ensure the engine is cool and the ignition is off.
2. Remove the air intake cover or cowling to access the carburetor mounting area. Take note of any linkage or choke cable positions.
3. Disconnect throttle linkage, choke cable, and any primer bulb or fuel lines attached to the carburetor body. Label connections if needed for reassembly.
4. Unbolt the old carburetor from the intake manifold using the appropriate wrench or socket. Carefully lift it away and inspect the mounting gasket.
5. Clean the intake manifold surface thoroughly to remove old gasket material and debris. Ensure a smooth, clean sealing surface.
6. Position the new carburetor onto the intake manifold, aligning the mounting holes. Install a new gasket if one is included or required.
7. Hand-tighten the mounting bolts first, then torque them evenly in a cross pattern to manufacturer specifications. Avoid over-tightening.
8. Reconnect the throttle linkage, choke cable, and fuel lines to the corresponding fittings on the new carburetor. Ensure all clips and clamps are secure.
9. Reattach the air intake cover or cowling, making sure all fasteners are seated properly.
10. Prime the fuel system by squeezing the primer bulb until firm. Check all connections for fuel leaks before starting the engine.
11. Start the engine and allow it to warm up to operating temperature. Adjust idle speed and mixture screws as necessary per your service manual.
12. Test the throttle response and verify smooth acceleration. Re-check all fasteners and connections after the initial run.

Troubleshooting & FAQ

How do I confirm this carburetor fits my engine?
Cross-reference your engine's model number and year with the compatibility table above, and verify that your original carburetor bears one of the listed OEM part numbers (3F0-03100, 3F0-03100-2, 3F0-03100-4, etc.). If your model appears in the table and the part numbers match, this carburetor will fit.

What are common signs that my carburetor needs replacement?
Typical symptoms include difficulty starting, rough idling, stalling at low RPM, poor throttle response, excessive fuel consumption, or fuel leaking from the carburetor body. If cleaning and rebuilding do not resolve these issues, replacement is recommended.

How often should I replace or service the carburetor?
Carburetor longevity depends on fuel quality, usage frequency, and storage practices. Regular cleaning and inspection every season are recommended; replace the unit if internal passages are corroded, jets are damaged, or performance cannot be restored through servicing.

Can I use this carburetor on a 4-stroke engine?
No, this carburetor is designed specifically for 2-stroke outboards. Installing it on a 4-stroke engine will result in improper fuel mixture and poor performance.

Do I need to adjust the carburetor after installation?
Yes, after installation you should adjust the idle speed and mixture screws according to your engine's service manual to ensure optimal performance and fuel efficiency. Initial settings may need fine-tuning once the engine reaches operating temperature.

Is this an OEM or aftermarket part?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.