3F0-03100-4 Carburetor Fits Tohatsu & Nissan 3.5B2, 3.5A2 (3.5 HP)

Product Overview

XR MARINE · CARBURETORS & REPAIR KITS

3F0-03100-4 Carburetor Fits Tohatsu, Nissan, Mercury & Mariner 3.5B2, 3.5A2 (3.5 HP) - XR Marine

This product is a replacement carburetor for the specified Tohatsu and Nissan 2.5 HP and 3.5 HP 2-stroke outboard models (2.5A2, 3.5A2, and 3.5B2), as well as specified Mercury and Mariner 2 HP, 2.5 HP, 3 HP, and 3.3 HP single-cylinder 2-stroke outboard applications.

It is a carburetor unit rather than a carburetor repair kit. Because horsepower alone is not enough to identify the right version, match the engine brand, exact model designation, cylinder configuration, and complete reference number including suffixes before ordering.

Product Specifications

Key product details for identification and comparison.

Fitment

The 3F0-03100-4 Carburetor from XR Marine fits Tohatsu and Nissan 2.5A2 (2.5 HP), 3.5A2 (3.5 HP), and 3.5B2 (3.5 HP) 2-stroke outboards, and fits Mercury and Mariner 2 HP, 2.5 HP, 3 HP, and 3.3 HP 2-stroke outboards when configured as single-cylinder engines in the applications listed below.

Verify the complete model designation on your engine identification plate against the individual entries below, compare the full OEM reference number including any suffixes, and observe the single-cylinder requirement for Mercury and Mariner engines. Horsepower alone is not sufficient to confirm fitment.

• Brand: Tohatsu (Nissan / Tohatsu Marine Outboard) | Model: 3.5B2 | Power: 3.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Tohatsu (Nissan / Tohatsu Marine Outboard) | Model: 3.5A2 | Power: 3.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Tohatsu (Nissan / Tohatsu Marine Outboard) | Model: 2.5A2 | Power: 2.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Nissan (Nissan / Tohatsu Marine Outboard) | Model: 3.5B2 | Power: 3.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Nissan (Nissan / Tohatsu Marine Outboard) | Model: 3.5A2 | Power: 3.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Nissan (Nissan / Tohatsu Marine Outboard) | Model: 2.5A2 | Power: 2.5 HP | Stroke: 2-Stroke
  ✓ Fits
• Brand: Mercury (Mercury Mariner) | Power: 3.3 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mercury (Mercury Mariner) | Power: 2.5 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mercury (Mercury Mariner) | Power: 2 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mercury (Mercury Mariner) | Power: 3 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mariner (Mercury Mariner) | Power: 3.3 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mariner (Mercury Mariner) | Power: 2.5 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mariner (Mercury Mariner) | Power: 2 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions
• Brand: Mariner (Mercury Mariner) | Power: 3 HP | Stroke: 2-Stroke | Restriction: Single-cylinder (cylinder_count: 1); model, year, and serial range not specified
  ! Check conditions

OEM & Part Number References

Use the complete reference number, including its suffix, when comparing parts. Reference numbers do not confirm that every version is interchangeable.

What's Included

Check the supplied components before planning your repair.

• Carburetor.

Contact XR Marine to confirm the supplied contents before ordering.

Installation Guide

General installation overview. Follow the service manual for your exact engine and carburetor configuration. Fuel-system work requires the appropriate skills and precautions.

1. Verify identification and prepare the engine: Confirm your engine model designation, 2-stroke single-cylinder configuration, and complete carburetor reference number before starting work. Shut off the engine, allow it to cool completely, isolate the fuel supply and ignition per your service manual, and work in a well-ventilated area away from ignition sources.
2. Remove the existing carburetor and compare interfaces: Document the routing and orientation of the fuel line, throttle linkage, choke linkage, and mounting hardware before removal. Remove the existing carburetor according to the factory service manual and compare the mounting flange, fuel inlet, and linkage attachment points side by side with the replacement carburetor.
3. Install, check for leaks, and perform manual-specified adjustments: Mount the replacement carburetor and reconnect the linkages and fuel line as specified in your service manual. Check that throttle and choke controls move freely without binding. Restore the fuel supply and inspect carefully for any fuel leaks before starting; test run the outboard only with proper cooling water supply and perform any idle or mixture adjustments required by your service manual.

Before You Order

A careful fitment check helps you choose the right part the first time.

• Match the full engine model designation on the identification plate.
• Check the individual application entry and any engine configuration or version restrictions, including the single-cylinder 2-stroke requirement for Mercury and Mariner engines.
• Compare the complete OEM reference number, including its suffix. Horsepower or appearance alone is not enough.
• Confirm the package contents and the quantity needed for your repair.
• Keep reference-number suffixes such as "-0", "-4", "-5", "A1", and "T06" when comparing parts; do not assume a number without an "A" suffix is interchangeable with the corresponding "A" version.

Need help checking fitment? Have your engine identification details, the existing part number and clear photos ready when you contact XR Marine.

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Frequently Asked Questions

Answers to common questions about this product and its application.