Tohatsu 50HP 2-Stroke Outboard Engine Parts

(21 products)

This page focuses on Tohatsu 2‑Stroke 50HP outboard engines and helps you find compatible parts and service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse our main Tohatsu collection, and at the bottom of this page you’ll find a quick link to start browsing parts for this engine. On the collection page, use the “Filter & Sort” controls to narrow by horsepower, year range, and part category.

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How to Identify Your 50HP Model

Find the nameplate/serial label on the clamp bracket or swivel bracket; record the exact model code and serial number.
Tohatsu 2‑stroke 50HP models are commonly labeled M50D2 with suffixes indicating features: shaft length (S/L), tiller vs. remote control, manual/electric start, and trim/tilt options (e.g., MF, EFTO, EPO, EPTO).
Auto‑mix (oil‑injected) variants typically have a visible remote oil tank and lines; pre‑mix versions do not.
These engines are 3‑cylinder, carbureted 2‑strokes sharing many service parts with the 40D2 family; verify year and options for best parts match.

Engine Overview

Tohatsu M50D2 Platform

Feature	Description
Configuration	Inline‑3, carbureted 2‑stroke, approx. 697 cc, through‑hub exhaust
Common Models	M50D2 MF (tiller/manual tilt), EFTO (remote/electric), EPO (auto‑mix), EPTO (auto‑mix with PTT); S/L shaft lengths
Advantages	Light weight and responsive; strong hole‑shot for small to mid‑size boats; simple carb serviceability
Notes	Typical WOT range about 5150–5850 rpm with 1.85:1 gear ratio; many wear items cross with 40D2. Auto‑mix models use an oil tank/pump—bleed and inspect lines/filters during service.

Routine Maintenance & Service Parts

Intervals below are general guidelines for typical recreational use; always follow your official service manual and adjust for heavy use, sandy/brackish water, or long storage.

Item	Interval*	Remarks	Parts Link
2‑Stroke Oil Supply (injection or pre‑mix)	Check each outing; service annually	Auto‑mix: verify tank level, lines, filter, and bleed air. Pre‑mix: 50:1 after break‑in; use TC‑W3 oil.	Tohatsu Outboard Parts
Spark Plugs	Inspect 50–100 hrs; replace as needed	Typical type for 50D2: NGK B8HS‑10/BR8HS‑10; check gap and torque per manual.	Spark Plugs
Fuel Filter / Water Separator	Inspect every 50 hrs; replace 100 hrs or seasonally	Drain/inspect for water and debris; replace if contaminated or restricted.	Fuel Filters
Water Pump Impeller / Kit	Every season or 100 hrs (sooner for sand/silt)	Restore cooling flow and overheat protection; inspect wear plate and housing.	Tohatsu Water Pump Repair Kits
Lower Unit Gear Oil	Every 100 hrs or at end of season	Replace with marine gear lube; check for water intrusion (milky oil) or metal fines.	Tohatsu Outboard Parts
Lower Unit Seals (reseal as needed)	As required (leaks, water in oil)	Use when pressure/vac tests fail or seals show wear.	Tohatsu Lower Unit Seal Kits
Anodes (corrosion protection)	Inspect each 50 hrs; replace when ~50–70% consumed	Do not paint or grease; verify tight hardware and good contact.	Anodes
Propeller & Cotter/Pin	Inspect often; replace if bent/chipped	Check for fishing line at seals; torque nut and use a new pin when removed.	Propellers

Frequently Used Parts Categories

Routine Service Kits – Service & Maintenance Kits
Cooling System – Tohatsu Water Pump Repair Kits
Lower Unit & Seals – Tohatsu Lower Unit Seal Kits
Fuel System – Fuel Filters
Ignition / Electrical – Electrical Items and Spark Plugs
Propellers – Propellers and Propeller Guards
Corrosion Protection – Anodes

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale stream / overheat alarm	Inspect water inlets for blockage; evaluate impeller age; confirm thermostat operation; verify hose/telltale is clear.	Water pump kit, impeller, thermostat, intake screens
Poor acceleration / power loss	Check fuel quality and filter, primer bulb firmness, plug condition/gap, and propeller damage/cavitation.	Fuel filter, spark plugs, carburetor kit, propeller
Hard starting / rough idle	Verify choke/enrichment, prime line until firm, inspect for air leaks, confirm correct plug type and gap.	Spark plugs, fuel pump/lines, carburetor service parts
Excessive smoke (2‑stroke)	Confirm correct oil ratio (pre‑mix) or oil pump setting (auto‑mix); use TC‑W3 oil; check for flooded cylinders.	2‑stroke oil, spark plugs, carburetor needle/seat
Gearcase noise / metal in gear oil	Inspect drained oil for water/metal; check prop shaft for fishing line; pressure/vac test for seal leaks.	Lower unit seal kit, prop thrust washer, shims/bearings (as required)

FAQs

Are parts interchangeable between different years or between 40D2 and 50D2?

Many wear parts (water pump components, some seals, fasteners) are shared across the 40D2/50D2 family. However, confirm by model code and serial number—ignition, carb jetting, and control/trim components can differ by option package and year.

When should I replace the impeller?

Inspect each season and replace every 100 hours or annually—earlier if operating in sand/silt, if the tell‑tale weakens, or after any overheat event. Full pump kits are recommended if the wear plate or cup shows scoring.

How often should gear oil be changed?

Typically every 100 hours or at the end of the season. Always service immediately if oil appears milky (water intrusion) or metallic. Replace gaskets and consider a reseal if pressure/vac tests fail.

What do you need to confirm part compatibility?

Please provide the exact model code (e.g., M50D2 with suffix), serial number, shaft length (S/L), control type (tiller/remote), and whether it’s pre‑mix or auto‑mix. A photo of the nameplate helps ensure a precise match.

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If you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.