Johnson 40HP 2-Stroke Outboard Engine Parts

(51 products)

This page is dedicated to Johnson 40 HP 2-Stroke outboard engines. Use it to find compatible parts and practical service information. You’ll find maintenance tips, commonly replaced parts, and troubleshooting guidance below. You can also browse the main Johnson/Evinrude collection, and at the bottom of this page you’ll find a quick way to start browsing parts for this engine. On the collection page, use the Filter & Sort controls to narrow results by horsepower, year range, and part category/section.

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How to Identify Your 40 HP Model

Find the model/serial number plate on the top outside edge of the clamp bracket or on the swivel bracket (port or starboard side).
Model codes typically include a base model, shaft length (S/L/XL), starting method (rope/electric), and a year/series suffix. Verify each character to ensure parts compatibility.
This 2‑stroke family was offered in short and long shaft lengths with tiller or remote controls. Confirm these options before ordering shift/steering parts or props.
If the engine has been repowered or the midsection swapped, always match parts to the exact model code on your bracket plate rather than the boat’s year.

Platform Overview

Johnson 40 HP 2‑Stroke (typical configuration)

Feature	Description
Configuration	Twin‑cylinder, carbureted 2‑stroke outboard; manual or electric start; remote or tiller steering.
Common Models	40 HP 2‑stroke variants produced across multiple years with short/long shafts and various control options; check bracket tag for exact code.
Advantages	Light weight, simple carburetion, strong low‑to‑midrange torque, widely supported service parts.
Notes	Use the exact model/year suffix to match ignition, carburetor, and cooling components. Propeller hub and pitch depend on shaft length and gear ratio.

Routine Maintenance & Service Parts

Intervals below are general guidelines for typical use. Always follow the official service manual for your specific model and operating conditions.

Item	Interval*	Remarks	Parts Link
Gear oil (lower unit)	Every 100 hrs or annually	Change more often after gearcase service or water intrusion checks.	Johnson/Evinrude Collection
Spark plugs	Inspect 50–100 hrs; replace as needed	Gap to spec; replace if fouled, worn, or cracked insulator.	Spark Plugs
Fuel filter / inline filter	Every 100 hrs or annually	Replace sooner with stale fuel or contamination; check primer bulb and hoses.	Fuel Filters
Water pump impeller / kit	Every 1–2 seasons (sooner in sandy/silty water)	Restore cooling flow and protect from overheat; inspect wear plate and housing.	Johnson/Evinrude Water Pump Kits
Anodes (zinc/aluminum/magnesium)	Inspect every 3 months; replace at ~50% wear	Choose alloy for your water type (salt/brackish/fresh).	Johnson/Evinrude Anodes
2‑stroke oiling (premix or oil injection)	Every trip (premix) / seasonally (injection inspection)	Premix 50:1 (2%) with TC‑W3 oil unless equipped with functional oil injection; inspect oil lines and filters if injected.	Hoses & Lines
Gearcase seals (pressure test)	Test annually; service if water in oil	Milky gear oil indicates intrusion; replace prop shaft/driveshaft seals as needed.	Lower Unit Seal Kits

Frequently Used Parts Categories

Routine Service – Johnson/Evinrude Service & Maintenance Kits
Cooling System – Water Pump Repair Kits
Fuel System – Fuel Filters
Ignition / Spark – Spark Plugs
Propulsion – Johnson/Evinrude Propellers
Gearcase Seals – Lower Unit Seal Kits
Corrosion Protection – Johnson/Evinrude Anodes

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak telltale or overheat alarm	Inspect intake screens for blockage; verify strong primer bulb; test thermostat; assess impeller condition.	Water pump kit, intake screen, thermostat, gaskets
Poor acceleration or power loss	Check for fouled plugs; restricted fuel filter; clogged carburetor jets; damaged prop or wrong pitch.	Spark plugs, fuel filter, carb kits, propeller
Hard starting / rough idle	Verify choke/enrichment function; inspect primer bulb and fuel lines; clean carb; check idle mixture and timing.	Fuel lines/hoses, fuel filter, carburetor kit, spark plugs
Excessive smoke	Confirm premix at 50:1; ensure choke not stuck closed; check float levels and needle/seat sealing.	Carburetor kit, choke components, fuel needles/seats
Gearcase noise or metal in gear oil	Check oil level and condition; pressure/vacuum test for leaks; inspect prop shaft for fishing line cutting seals.	Lower unit seal kit, bearings, shims, gear oil

FAQs

Are parts interchangeable between different years or variants?

Some service items interchange across years, but ignition, carburetion, and cooling parts can change with model updates. Always confirm using the exact model code and suffix from your clamp/swivel bracket tag.

When should I replace the impeller?

As a rule of thumb, replace the impeller every 1–2 seasons, or immediately if the telltale is weak, you overheated, or you operate in sandy/silty water. Inspect the wear plate and housing each time.

How often should I change lower unit gear oil?

Change gear oil every 100 hours or annually. If the oil looks milky, water has entered—pressure test the gearcase and service seals before returning to use.

What information do you need to confirm part compatibility?

Please provide the full model code from the bracket plate, shaft length, start method (manual/electric), and any photos of the nameplate and the part you’re replacing.

Ready to find parts by horsepower, year, and model? Start in our main Johnson/Evinrude collection and use the filters to narrow down to your 40 HP 2‑stroke.

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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.