Yamaha 13.5HP 2-Stroke Outboard Engine Parts

(7 products)

This page is dedicated to Yamaha 2-Stroke 13.5HP outboard engines. Use it to find compatible parts, routine service information, maintenance tips, commonly replaced items, and troubleshooting guidance. You can also browse the main Yamaha collection, and at the bottom of this page you’ll find quick links to start browsing parts specific to this engine. On the collection pages, use the “Filter & Sort” controls to narrow results by horsepower, year range, and part category/section.

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How to Identify Your 13.5HP Model

Locate the nameplate/serial sticker on the transom bracket or swivel bracket. It lists the model code, serial number, and often the shaft length.
Read the suffix letters in the model code: they typically indicate shaft length (S ≈ 15 in, L ≈ 20 in), tiller vs. remote control, and manual vs. electric start. Match these to parts for proper fit.
Confirm it is a 2‑stroke model. These engines are carbureted and either premix fuel/oil or use an oil-injection reservoir; the parts differ from 4‑stroke models.
Note year/market differences. Small 2‑stroke Yamaha models in the ~9.9–15 hp class share many wear parts, but impellers, gearcase seals, and ignition pieces can vary by year and shaft length.

Engine Overview

Small 2‑Stroke Outboard (≈13.5HP, 9.9–15 hp class)

Feature	Description
Configuration	Inline‑2, carbureted 2‑stroke; manual or electric start; short (S) or long (L) shaft options.
Common Models	Yamaha 13.5HP 2‑Stroke variants; many parts are similar to Yamaha 9.9–15 hp 2‑stroke models—verify by model code and shaft length.
Advantages	Light weight, simple maintenance, good low‑to‑midrange torque for dinghies and small boats.
Notes	Impeller and gearcase seal kits can differ across years/shafts. Always match parts to the exact model code, serial number, and shaft length.

Routine Maintenance & Service Parts

Intervals below are general guidelines for small 2‑stroke outboards. Always follow your official Yamaha service manual for model‑specific procedures and specifications.

Item	Interval*	Remarks	Parts Link
Gear oil (lower unit)	Every 100 hrs or annually	Inspect for water (milky oil) or metal; replace drain/fill gaskets when serviced.	Yamaha Lower Unit Seal Kits
Spark plugs	Inspect 50 hrs; replace 100 hrs or annually	Use the correct heat range; gap per manual. Fouling indicates mixture or fuel issues.	Spark Plugs
Fuel filter / inline filter	Every 100 hrs or annually	Replace or clean; check primer bulb and hoses for cracking or air leaks.	Fuel Filters
Water pump impeller / kit	200 hrs or 2–3 seasons	Inspect annually; replace sooner if weak tell‑tale or overheat warnings occur.	Yamaha Water Pump Repair Kits
Anodes (sacrificial)	Inspect each 50 hrs or every season	Replace when ~50% consumed; choose alloy for your water (aluminum/magnesium/zinc).	Yamaha Anodes
Propeller & hardware	Each season or after impact	Remove prop, check for fishing line at seals; grease splines; inspect cotter/nut.	Yamaha Propellers
2‑Stroke oil system (premix or injection)	Check every trip; service annually	Verify reservoir level and hose condition; if premix, follow the ratio in your manual.	Hoses

*Intervals are general recommendations; service environment and hours may require shorter intervals.

Frequently Used Parts Categories

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

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale or overheat alarm	Clear the intake screen; verify strong tell‑tale; inspect impeller and thermostat.	Water pump kit, thermostat, intake screen, anodes
Hard starting / rough idle	Check fuel freshness, primer bulb, choke/enrichment; inspect/replace spark plugs.	Spark plugs, inline fuel filter, carburetor kit, fuel hoses
Poor acceleration or power loss	Inspect prop for damage/slip; check compression and ignition; verify carb balance/cleanliness.	Propeller, carb gaskets/jets, spark plugs, fuel filter
Excessive smoke (2‑stroke)	Confirm premix ratio or oil‑injection setting; look for stuck choke or leaking needle/seat.	Oil‑injection hoses, carburetor kit, choke components
Gearcase noise or metal in gear oil	Check oil for water/metal; inspect prop‑shaft seals for fishing line damage.	Lower unit seal kit, bearings, prop‑shaft seals

FAQs

Are parts interchangeable between different years or nearby horsepower models?

Many wear items in the 9.9–15 hp Yamaha 2‑stroke class are similar, but there are year, shaft length, and start/control differences that affect fit. Match parts to your exact model code and serial number for best results.

When should I replace the impeller?

As a preventive measure every 2–3 seasons or ~200 hours. Replace sooner if the tell‑tale weakens, you run sandy/silty water, or anytime the engine overheats.

How often should I change gear oil in the lower unit?

At least annually or every 100 hours. Inspect the oil for milky color (water intrusion) or metal. Replace drain/fill gaskets each service and address any seal issues immediately.

What information do you need to confirm part compatibility?

The full model code, serial number, shaft length (S/L), start type (manual/electric), and control type (tiller/remote). Photos of the nameplate and the part needing replacement are also helpful.

Ready to find parts? Browse the main Yamaha collection and filter by horsepower, year, and model to locate parts for your 13.5HP 2‑Stroke outboard.

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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.