3BJ-03100-0 Carburetor Fits Nissan / Tohatsu Marine Outboard MFS20C, MFS15C

Product Overview

XR MARINE · CARBURETORS & REPAIR KITS

3BJ-03100-0 Carburetor Fits Nissan / Tohatsu Marine Outboard MFS20C, MFS15C

This product is a replacement carburetor for the listed 4-stroke outboard applications, including Tohatsu / Nissan model references MFS20C, MFS15C, F15C, F20C, and NSF15C, as well as the specified Mercury / Mariner twin-cylinder 4-stroke application group. It is supplied as a carburetor unit rather than a carburetor repair kit.

When selecting a replacement or checking the listed 15 HP-to-20 HP conversion application on twin-cylinder, tiller-controlled 4-stroke engines, verify the complete original carburetor reference number, cylinder count, and control configuration before ordering.

Product Specifications

Key product details for identification and comparison.

Fitment

The 3BJ-03100-0 Carburetor from XR Marine fits Nissan / Tohatsu Marine Outboard MFS20C, MFS15C, F15C, F20C, and NSF15C 4-stroke outboards, and fits Mercury / Mariner 4-stroke outboards subject to the 2-cylinder and tiller-control conversion conditions in the applications listed below.

Match the full model designation on your engine identification plate against each individual entry below, compare the complete original carburetor reference number with all prefixes and suffixes intact, and verify cylinder count and tiller versus remote control restrictions. Horsepower alone cannot confirm carburetor compatibility.

• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS20C | Stroke: 4-Stroke | Notes: Tohatsu MFS20C, 4-Stroke. The source lists 15 HP and 20 HP in the same application group but does not assign either horsepower individually to this model.
  ✓ Fits
• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS15C | Stroke: 4-Stroke | Notes: Tohatsu MFS15C, 4-Stroke. The source lists 15 HP and 20 HP in the same application group but does not assign either horsepower individually to this model.
  ✓ Fits
• Brand: Nissan / Tohatsu Marine Outboard | Model: F15C | Stroke: 4-Stroke | Notes: Tohatsu F15C, 4-Stroke. The source lists 15 HP and 20 HP in the same application group but does not assign either horsepower individually to this model; whether F15C is an MFS15C alias is unconfirmed.
  ✓ Fits
• Brand: Nissan / Tohatsu Marine Outboard | Model: F20C | Stroke: 4-Stroke | Notes: Tohatsu F20C, 4-Stroke. The source lists 15 HP and 20 HP in the same application group but does not assign either horsepower individually to this model; whether F20C is an MFS20C alias is unconfirmed.
  ✓ Fits
• Brand: Nissan / Tohatsu Marine Outboard | Model: NSF15C | Stroke: 4-Stroke | Notes: Tohatsu NSF15C, 4-Stroke. The source lists 15 HP and 20 HP in the same application group but does not assign either horsepower individually to this model; exact brand designation requires clarification.
  ✓ Fits
• Brand: Mercury Mariner | Model: Outboard; exact model not specified | Stroke: 4-Stroke | Conditions: Cylinder count: 2; 15–20 HP (source range retained; no intermediate horsepower applications individually confirmed).
  ! Check conditions
• Brand: Mercury Mariner | Model: 15 HP-to-20 HP conversion application; exact model not specified | Stroke: 4-Stroke | Conditions: Cylinder count: 2; Control configuration: Tiller control; stated replaced 15 HP carburetor references 853720T14, 853720T19, and 8M0109533. The source states a claimed 20 HP output; actual outcome and engine-specific requirements are not established as universal.
  ! Check conditions

Fitment to Confirm

• Brand: Mercury Mariner | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: Cylinder count: 2; stated horsepower range: 15 HP–20 HP (continuity of the range is not specified). Secondary record lists 14 and year 1990; confirm exact engine details and carburetor reference before ordering.
  ? Confirm fitment
• Brand: Mercury Mariner | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: Cylinder count: 2; Control type: Tiller control; conversion starting power: 15 HP; conversion stated target power: 20 HP; stated replaced original carburetor references 853720T14, 853720T19, and 8M0109533. Secondary record lists 14 and year 1990; confirm exact engine details before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS20C | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: The source lists 15 HP and 20 HP for the model group; secondary record lists 14 and year 1990. Confirm exact engine details before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS15C | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: The source lists 15 HP and 20 HP for the model group; secondary record lists 14 and year 1990. Confirm exact engine details before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: F15C | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: Source application group: Tohatsu Outboard model group; individual make and horsepower assignment are not confirmed. Secondary record lists 14 and year 1990.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: F20C | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: Source application group: Tohatsu Outboard model group; individual make and horsepower assignment are not confirmed. Secondary record lists 14 and year 1990.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: NSF15C | Power: 14 | Year: 1990 | Stroke: 4-Stroke | Conditions: Source application group: Tohatsu Outboard model group; individual make and horsepower assignment are not confirmed. Secondary record lists 14 and year 1990.
  ? Confirm fitment

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 (OEM reference: 853720T15 ) — Included.

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 that the engine model, cylinder count, control type (tiller versus remote control), and existing carburetor part number match your application. Shut off the engine, allow it to cool completely, disconnect the fuel supply and battery/ignition lead according to the service manual, and work in a well-ventilated area away from ignition sources.
2. Document connections and compare the carburetor: Record the routing and orientation of all fuel lines, breather hoses, and throttle or choke linkages before removal. Remove the existing carburetor following the service manual and compare the mounting flanges, linkage arms, and fuel inlet orientation against the replacement carburetor.
3. Install, inspect for leaks, and verify operation: Mount the carburetor and reconnect the linkages and fuel lines according to the service manual, checking that the throttle and choke move smoothly without binding. Restore the fuel supply and inspect all connections for fuel leaks before starting. Run the engine only with the proper cooling water supply connected, and perform any idle or linkage adjustments specified in your service manual. Stop the engine immediately if any fuel leak, linkage binding, or abnormal running occurs.

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 year entry and any serial-number or version restrictions.
• 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.
• For a 15 HP-to-20 HP conversion application, verify that your engine is a twin-cylinder, tiller-controlled, 4-stroke configuration and match your original 15 HP carburetor reference (853720T14, 853720T19, or 8M0109533) before purchasing.

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

Why XR Marine

Frequently Asked Questions

Answers to common questions about this product and its application.