Honda Marine 4-Stroke 35-50HP Outboard Engine Parts

(3 products)

This page is for Honda 4-Stroke 35–50HP outboard engines. Use it to find compatible parts and service information, including maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse the main Honda parts collection. Scroll to the bottom of this page to start browsing parts for this engine, and on the collection page use the Filter & Sort controls to narrow results by horsepower, year range, and part category.

Browse All Honda Parts

How to Identify Your 35–50HP Model

Locate the model/serial plate on the transom bracket or swivel bracket. It includes the model (e.g., BF40) and a serial number.
Read the full model code and suffix: letters often indicate generation (A/D/E), shaft length (S/L/X), steering/control type (tiller/remote), and options like power trim.
4‑Stroke Honda BF40/BF50 models exist in carbureted and later EFI (PGM‑FI) versions. EFI models have an electric high‑pressure fuel pump and fuel rail; carb versions have individual carburetors.
“Power Thrust” models (BFP50) use a larger gearcase/prop for better thrust; many parts are shared with BF50, but some propeller and gearcase items differ.

Platform Overview

Carbureted Generation (BF35A / BF40A / BF50A)

Feature	Description
Configuration	Inline‑3, 4‑stroke, carbureted induction, mechanical controls.
Common Models	BF35A, BF40A, BF50A (variations by shaft length and trim/tilt).
Advantages	Simple fuel system, straightforward maintenance, durable gearcase.
Notes	Many wear parts (impeller kits, anodes, plugs) cross over within the A‑series; carb rebuild, ignition, and some cooling parts can be generation‑specific.

EFI Generation (BF40D / BF50D / BFP50)

Feature	Description
Configuration	Inline‑3, 4‑stroke with PGM‑FI (EFI), electronic fuel pump and ECU.
Common Models	BF40D, BF50D/E and BFP50 (Power Thrust) variants.
Advantages	Improved fuel economy, cleaner emissions, easier starts, strong mid‑range torque.
Notes	Fuel filtration and sensors differ from carb versions; BFP gearcase and prop options vary. Always verify by full model code and serial.

Routine Maintenance & Service Parts

Intervals below are general 4‑stroke guidelines. Always follow your specific Honda service manual and local operating conditions.

Item	Interval*	Remarks	Parts Link
Engine oil & filter	Every 100 hours or annually	Warm engine before draining; replace crush washer if applicable.	Oil Filters
Gear oil (lower unit)	Every 100 hours or annually	Inspect for water intrusion (milky oil) and metal on magnet.	Honda Outboard Parts
Spark plugs	Inspect 100 hours; replace 200 hours or as needed	Check gap and insulator color; replace if fouled or worn.	Spark plug
Fuel filter / water separator	Every 100–200 hours or annually	EFI models are more sensitive to restriction; drain water separator regularly.	Fuel Filters
Water pump impeller / kit	Every 200 hours or 2–3 seasons	Replace sooner if weak tell‑tale or overheat alarm occurs.	Honda Water Pump Repair Kits
Anodes (internal & external)	Inspect every 50 hours; replace when 50% depleted	Use the correct alloy for your water (fresh/brackish/salt).	Anodes
Thermostat inspection	Every 200 hours or 2 seasons	Replace if stuck, corroded, or temperature control is unstable.	Honda Outboard Parts

Frequently Used Parts Categories

Routine Service: Service & Maintenance Kits
Cooling System: Honda Water Pump Repair Kits
Fuel System: Fuel Filters
Ignition / Electrical: Electrical Items
Gearcase & Seals: Honda Lower Unit Seal Kits
Propulsion: Propellers
Corrosion Protection: Anodes

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale or overheat alarm	Inspect intake screen, tell‑tale hose for blockage, and thermostat function.	Water pump kit, thermostat, intake screen, anodes.
Poor acceleration or power loss	Check prop condition, fuel quality, and filter restriction; verify plug condition.	Propellers, fuel filter, spark plugs.
Hard starting or rough idle	Confirm fresh fuel, battery voltage, and clean plugs; on EFI, check for clogged low/high‑pressure filters.	Fuel filter, spark plugs, electrical items, sensors.
Gearcase noise or metal in gear oil	Inspect drain plug magnet and oil color; pressure test for leaking seals.	Lower unit seal kit, propeller hardware, gear oil (service).
Charging/battery not keeping up	Test battery, clean grounds, inspect rectifier‑regulator connections.	Electrical items, sensors.

FAQs

Are parts interchangeable between different years or platforms?

Many wear items interchange within the same generation (e.g., BF40A/BF50A or BF40D/BF50D), but EFI vs. carbureted components, Power Thrust gearcase parts, and some cooling/fuel parts differ. Verify by full model code and serial.

When should the impeller be replaced?

As a preventive measure, replace the impeller every 2–3 seasons or ~200 hours. Replace sooner if the tell‑tale weakens, you run in sandy/silty water, or an overheat event occurs.

How often should gear oil be changed?

Change lower unit gear oil every 100 hours or annually. Inspect for water intrusion (milky appearance) and metal on the magnetic plug; address leaking seals promptly.

What information do you need to confirm part compatibility?

Please provide the full model code, serial number, horsepower, shaft length, control type (tiller/remote), and a brief description or photo of the part location.

Ready to find parts? Browse the main Honda collection and filter by horsepower, year, and model to zero in on compatible items for your 35–50HP engine.

Shop Honda Outboard Parts

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.