Yamaha 30HP 2-Stroke Outboard Engine Parts

(70 products)

This page covers Yamaha 30HP 2‑Stroke outboard engines. Use it to find compatible parts and service information, including maintenance tips, common replacement items, and troubleshooting guidance. You can also browse the main Yamaha collection. Scroll to the bottom of the 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 Yamaha Parts

How to Identify Your 30HP Model

Locate the nameplate/serial label on the port clamp bracket. Record the model code and serial number.
Model codes and suffixes indicate features such as shaft length (S/L/X), control type (tiller vs. remote), and start type (manual vs. electric). Examples you may see include 30HMH, 30HW, 30HWH, and 30HWC.
These are 2‑Stroke twins. If your engine is 4‑Stroke, you are on the wrong page; browse the Yamaha collection and filter for 4‑Stroke instead.
Compare your plate information with the owner’s/service manual to confirm year range and options before ordering parts.

Engine Overview

Yamaha 30HP 2‑Stroke Platform

Feature	Description
Configuration	Inline‑2, 496 cc, loop‑charged reed‑valve, carbureted 2‑Stroke; CDI ignition; water‑cooled.
Common Models	30HMH, 30HWH, 30HW, 30HWC (various shaft lengths and control/start options).
Operating Range	Full‑throttle 4,500–5,500 RPM; typical gear ratio ~2.08:1; aluminum props commonly 9 7/8" diameter with a range of pitches.
Advantages	Light weight, simple service, strong hole‑shot for small boats, broad parts availability.
Notes	Pre‑mix fuel/oil (TC‑W3) typically 50:1 after break‑in; thermostat begins to open near 48–52 °C; use hypoid gear oil GL‑4 SAE 90 in the gearcase.

Routine Maintenance & Service Parts

Intervals below are general guidelines; always follow your official Yamaha service manual and adjust based on usage (salt, silt, storage, etc.).

Item	Interval*	Remarks	Parts Link
2‑Stroke Oil (TC‑W3) / Fuel Mix	Every refuel	Typical 50:1 after break‑in; use fresh fuel, correct octane. For initial break‑in some manuals specify richer mix.	Yamaha Service & Maintenance Kits
Gear Oil (Lower Unit)	100 hrs or annually	GL‑4 SAE 90; inspect for water/metal; capacity approx. 320 ml on many 25/30HP twins.	Yamaha Lower Unit Seal Kits
Spark Plugs	Inspect 50 hrs; replace ~100 hrs	Gap 0.9–1.0 mm; use correct heat range for your sub‑model; replace if fouled or worn.	Spark Plugs
Fuel Filter (inline/under‑cowl)	Inspect 50 hrs; replace as needed	Check for debris/water; keep spare element on board.	Fuel Filters
Water Pump Impeller/Kit	100 hrs or annually	Replace sooner if tell‑tale weak, overheat alarm, or sand/silt use.	Yamaha Water Pump Repair Kits
Anodes (external/internal)	Inspect 50 hrs; replace when 50% gone	Do not paint or grease; choose alloy for your water type (salt/brackish/fresh).	Yamaha Anodes
Thermostat	Inspect 100 hrs	Opens around 48–52 °C on many models; replace if sticky or corroded.	Yamaha Outboard Parts
Propeller & Cotter Pin	Check every outing	Inspect blades and hardware; keep spare cotter pin; verify pitch for proper WOT RPM.	Yamaha Propellers

Frequently Used Parts Categories

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

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale or overheat alarm	Inspect intake screens for debris; verify water pump impeller condition; confirm thermostat isn’t stuck.	Water pump kit, thermostat, intake screen/cover
Poor acceleration / power loss	Check fuel freshness and filter; inspect spark plugs; verify prop condition/pitch; confirm throttle opens fully.	Spark plugs, fuel filter, carb service kit, propeller
Hard starting / rough idle	Confirm correct fuel/oil mix; use proper choke procedure; check idle speed and air leaks on gaskets/hoses.	Spark plugs, fuel filter, gasket set, choke components
Excessive smoke (2‑Stroke)	Verify premix ratio; ensure choke isn’t stuck on; check for flooded carburetor.	2‑Stroke oil, choke linkage/solenoid, carb needle/seat
Gearcase noise or metal in gear oil	Check oil level/condition; inspect prop shaft for fishing line; test for seal leaks and bearing wear.	Gear oil, lower unit seal kit, bearings, shims

FAQs

Are parts interchangeable between different years or 25/30HP platforms?

Many components are shared across Yamaha 25/30HP 2‑Stroke twins, but details (shaft length, controls, charging, carb/jetting) can differ. Always match by model code and serial number, and confirm dimensions where relevant.

When should I replace the water pump impeller?

As a rule of thumb, every 100 hours or annually—earlier if you run in sand, silt, or see a weak tell‑tale, steam, or overheat alarms. Consider the full pump kit if the housing or wear plate shows grooves.

How often should the gear oil be changed?

Typically every 100 hours or at least once per year. Inspect drained oil for water (milky) or metal. If contaminated, pressure‑test and reseal the gearcase before refilling.

What information do you need to confirm part compatibility?

Please provide the full model code, serial number, shaft length (S/L/X), control type (tiller/remote), and start/charge options. Photos of the nameplate and the part being replaced also help.

Ready to find parts by horsepower, year, and model? Browse the main Yamaha collection and use the filters to zero in on compatible components.

Shop Yamaha 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.