Yamaha 3.5HP 2-Stroke Outboard Marine Engine Parts

(2 products)

This page is dedicated to Yamaha 2‑Stroke 3.5HP outboard engines. Use it to quickly find compatible parts and practical service information. Below you’ll find maintenance tips, commonly replaced parts, and troubleshooting guidance. You can also browse our main Yamaha collection any time. Scroll to the bottom of this page to start browsing parts for this engine, and remember you can use the “Filter & Sort” controls on the collection page to narrow results by horsepower, year range, and part category/section.

Browse All Yamaha Parts

How to Identify Your 3.5HP Model

Nameplate location: Look on the transom bracket or swivel bracket for a riveted plate with the model code and serial number.
Reading the code: The model string typically indicates horsepower, stroke type, shaft length (S/L/XL), and control/start style (manual vs. electric). Use the full code and serial to confirm parts.
2‑Stroke cues: No engine oil dipstick or sump. Engine uses premixed fuel/oil or an oil‑injection system. Spark plug access is simple and there’s a tell‑tale cooling water stream at idle.
Year and shaft length: Suffix letters often denote year revisions and shaft length; verify these details before ordering water pump and drive parts.

Engine Overview

Portable 3–4 HP Class 2‑Stroke

Feature	Description
Configuration	Single‑cylinder, carbureted 2‑stroke, manual start, tiller steer; water‑cooled with rubber impeller pump.
Common Models	Portable 3–4 HP 2‑stroke variants with short or long shaft; details vary by production year and market.
Advantages	Very light weight, simple maintenance, easy to service in the field, strong low‑speed thrust for dinghies and tenders.
Notes	Confirm shaft length and cooling‑system parts by model code. Many wear items (impeller, plugs, anodes) are shared across nearby horsepower ranges, but verify before purchase.

Routine Maintenance & Service Parts

Intervals below are general guidelines for small 2‑stroke portables. Always follow your official Yamaha service manual for exact procedures and schedules.

Item	Interval*	Remarks	Parts Link
Gear oil (lower unit)	Every 100 hours or annually	Inspect for metal or milky oil; replace seals if water intrusion is found.	Yamaha Outboard Parts
Spark plugs	Inspect every 50 hours; replace annually	Set to spec; replace if fouled or worn.	Spark Plugs
Fuel filter / inline screen	Every 100 hours or annually	Replace or clean; check portable tank pickup and venting.	Fuel Filters
Water pump impeller or kit	Every 2–3 seasons (sooner in sandy/silty water)	Restore cooling performance; replace housing/keys as needed.	Yamaha Water Pump Repair Kits
Anodes (internal/external)	Inspect every 50 hours; replace when 50% consumed	Match anode type to your waters (salt/brackish/fresh).	Yamaha Anodes
Carburetor clean/rebuild	As needed after storage or if running rough	Clean jets and passages; renew gaskets/needle/seat.	Carburetor
Fuel/oil premix	Every refuel	Use the mix ratio specified by Yamaha (commonly 50:1 with TC‑W3 oil); use fresh fuel.	Yamaha Service & Maintenance Kits
Propeller & shear pin	Inspect every 50 hours and after impacts	Check for bent blades and worn pins; keep a spare aboard.	Yamaha Propellers

Frequently Used Parts Categories

Routine Service – Yamaha Service & Maintenance Kits
Cooling System – Yamaha Water Pump Repair Kits
Fuel System – Fuel Filters
Carburation – Carburetor
Ignition / Electrical – Electrical Items
Propellers & Hardware – Yamaha Propellers
Lower Unit Seals – Yamaha Lower Unit Seal Kits

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale or overheat alarm	Inspect intake screen for debris; verify impeller condition; confirm thermostat operation.	Water pump kit, intake screen, thermostat
Poor acceleration or power loss	Check propeller and shear pin; replace fuel and filter; clean carburetor jets; verify tank venting.	Propeller, shear pin, fuel filter, carburetor repair components
Hard starting / rough idle	Refresh fuel; confirm choke/enrichment; inspect spark plug; check for air leaks at fuel fittings.	Spark plug, carb kit, fuel line and connectors
Excessive smoke	Verify premix ratio; check for flooded carburetor; inspect plug heat range and gap.	Spark plug, carburetor needle/seat, fuel
Gearcase noise or milky gear oil	Drain and inspect oil; pressure test lower unit; replace prop shaft/driveshaft seals if leaking.	Lower unit seal kit, gear lube

FAQs

Are parts interchangeable across different years?

Many wear parts for small Yamaha 2‑stroke portables are shared across adjacent model years, but changes in shaft length, cooling components, and carburetor variants can affect fit. Always confirm with the full model code and serial.

How often should I replace the impeller?

As a rule of thumb, every 2–3 seasons or 200–300 hours. Replace sooner if operating in sandy or silty water, or whenever the tell‑tale weakens.

How often should gear oil be changed?

Change at least once per season or every 100 hours. If the drained oil looks milky or contaminated, pressure‑test the gearcase and service the seals before returning to service.

What information helps confirm part compatibility?

Provide the full model code, serial number, shaft length, and any notable features (manual vs. electric start, remote vs. tiller). Photos of the nameplate and the part needing replacement are also very helpful.

Ready to find parts for your Yamaha 3.5HP 2‑Stroke? Browse the main Yamaha collection by horsepower, year, and model to locate the correct components.

Shop Yamaha Outboard Parts

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