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

Product Overview

XR MARINE · CARBURETORS & REPAIR KITS

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

This product is a complete carburetor replacement—not a carburetor repair kit—for specified 4-stroke outboard applications, including listed Nissan / Tohatsu MFS20C, MFS15C, F15C, F20C, and NSF15C models, as well as specified twin-cylinder Mercury / Mariner 4-stroke applications.

It is also referenced for a 15 HP-to-20 HP conversion application on twin-cylinder, tiller-controlled, 4-stroke Mercury / Mariner outboards replacing original 15 HP carburetor numbers 853720T14, 853720T19, and 8M0109533. Always verify the full engine model designation, control configuration, and complete original carburetor part number before ordering.

Product Specifications

Key product details for identification and comparison.

Fitment

The 3BJ-03100-0 Carburetor from XR Marine fits Nissan / Tohatsu MFS20C, MFS15C, F15C, F20C, and NSF15C 4-Stroke outboards, as well as Mercury / Mariner 4-Stroke 2-cylinder outboards (including tiller-controlled 15 HP-to-20 HP conversion configurations) in the applications listed below.

Match the full model designation on your engine identification plate against the individual entries below, compare the complete OEM part number including all prefixes and suffixes, and verify cylinder count and control configuration restrictions. Horsepower alone cannot confirm carburetor compatibility.

• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS20C | Stroke: 4-Stroke | Note: 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 | Note: 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 | Note: Listed in the Tohatsu Outboard application group (15 HP and 20 HP listed for the group without individual model assignment; whether F15C is an MFS15C alias is unconfirmed).
  ! Check conditions
• Brand: Nissan / Tohatsu Marine Outboard | Model: F20C | Stroke: 4-Stroke | Note: Listed in the Tohatsu Outboard application group (15 HP and 20 HP listed for the group without individual model assignment; whether F20C is an MFS20C alias is unconfirmed).
  ! Check conditions
• Brand: Nissan / Tohatsu Marine Outboard | Model: NSF15C | Stroke: 4-Stroke | Note: Listed in the Tohatsu Outboard application group (15 HP and 20 HP listed for the group without individual model assignment; exact brand designation requires clarification).
  ! Check conditions
• Brand: Mercury Mariner | Model: Outboard (exact model not specified) | Power: 15–20 HP (source range retained; no intermediate horsepower applications individually confirmed) | Stroke: 4-Stroke | Restriction: Cylinder count: 2
  ! Check conditions
• Brand: Mercury Mariner | Model: 15 HP-to-20 HP conversion application (exact model not specified) | Stroke: 4-Stroke | Restriction: Cylinder count: 2; Control configuration: Tiller control; replaces 15 HP original carburetor references 853720T14, 853720T19, and 8M0109533 (source states a claimed 20 HP output; actual outcome and engine-specific requirements are not established as universal)
  ! Check conditions

Fitment to Confirm

• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS20C | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Note: Secondary source table lists 14 HP and year 1990 alongside the 15 HP / 20 HP model group note; confirm exact engine year, horsepower, and OEM carburetor number before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: MFS15C | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Note: Secondary source table lists 14 HP and year 1990 alongside the 15 HP / 20 HP model group note; confirm exact engine year, horsepower, and OEM carburetor number before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: F15C | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Restriction: Source application group: Tohatsu Outboard model group; individual make, year 1990, and 14 HP assignment require confirmation before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: F20C | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Restriction: Source application group: Tohatsu Outboard model group; individual make, year 1990, and 14 HP assignment require confirmation before ordering.
  ? Confirm fitment
• Brand: Nissan / Tohatsu Marine Outboard | Model: NSF15C | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Restriction: Source application group: Tohatsu Outboard model group; individual make, year 1990, and 14 HP assignment require confirmation before ordering.
  ? Confirm fitment
• Brand: Mercury Mariner | Model: Model not specified | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Restriction: Cylinder count: 2; stated horsepower range: 15 HP–20 HP (continuity not specified); secondary table entry with 14 HP and year 1990 requires confirmation against engine serial and OEM part number.
  ? Confirm fitment
• Brand: Mercury Mariner | Model: Model not specified (15 HP-to-20 HP conversion application) | Power: 14 HP | Year: 1990 | Stroke: 4-Stroke | Restriction: Cylinder count: 2; Control type: Tiller control; conversion starting power: 15 HP; stated target power: 20 HP; stated replaced original carburetor references 853720T14, 853720T19, and 8M0109533; secondary table entry with 14 HP and year 1990 requires confirmation.
  ? 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.

Contact XR Marine to confirm the exact supplied package quantity 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: Before removing any parts, match the engine identification plate, control type (tiller versus remote control), and complete original carburetor reference number against the replacement carburetor. Ensure the engine is shut off and cool, disconnect the fuel supply and battery/ignition according to your service manual, and work in a well-ventilated area away from ignition sources.
2. Document routing and remove the existing carburetor: Label or photograph the fuel hose routing, throttle linkage, choke/enrichment connections, and mounting hardware orientation. Remove the existing carburetor assembly per the service manual and compare its mounting flange, linkage arms, and fuel inlet orientation directly against the replacement unit.
3. Install, check linkages, and test with cooling water: Mount the replacement carburetor and reconnect all linkages and fuel lines according to the service manual specifications. Verify that the throttle and choke operate smoothly through their full range without binding. Prime the fuel system to check for fuel leaks before starting, then run the engine with proper cooling water supply and perform any idle or linkage adjustments specified in your service manual. Shut down immediately if any leak or abnormal operation 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 Mercury / Mariner 15 HP-to-20 HP conversion applications, confirm that your engine is a 4-stroke, twin-cylinder, tiller-controlled model and matches the listed 15 HP carburetor numbers (853720T14, 853720T19, or 8M0109533).
• Keep all letters, hyphens, and suffixes when comparing Tohatsu and Mercury part numbers; similar-looking numbers for remote-control or different cylinder configurations are not interchangeable.

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.