WAHOO 4-Stroke 15-20HP Outboard Marine Engine Parts

(1 products)

This page covers Selva WAHOO 4‑Stroke 15–20HP outboard engines. Use it to find compatible parts and practical service information, including maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse our main Selva parts selection. 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 Service & Maintenance Kits

How to Identify Your 15–20HP Model

Locate the nameplate/serial plate on the transom bracket or swivel bracket. Note the model designation and serial number.
Read the full model code and suffix: shaft length (S/L), tiller vs remote control, and starting method (manual/electric) affect rigging and gearcase parts.
For 4‑stroke variants, confirm whether your engine is carbureted or EFI; fuel and ignition components may differ by market and year.
Many wear items interchange between 15HP and 20HP in this class, but always confirm against your serial plate before ordering.

Engine Overview

Small 4‑Stroke Twin (15–20HP Class)

Feature	Description
Configuration	Inline‑2, SOHC, water‑cooled 4‑stroke; offered as carbureted or EFI depending on year and market.
Common Models	Examples include Selva Wahoo 15/20 and Dolphin 15 models within the 15–20HP family.
Advantages	Quiet operation, good fuel economy, and straightforward upkeep for tenders and small craft.
Notes	Many service parts are shared between 15HP and 20HP variants. Verify by model/serial. Shaft length (short/long) and control type can change propeller, gearcase, and rigging parts.

Routine Maintenance & Service Parts

Intervals below are typical guidelines for small recreational 4‑stroke outboards. Always follow the official service manual for your exact model and operating conditions.

Item	Interval*	Remarks	Parts Link
Engine oil + filter	First 20 hours, then every 100 hours or annually	Use marine‑grade oil; replace drain plug crush washer where applicable.	Oil Filters
Gear oil (lower unit)	Every 100 hours or annually	Inspect for metal fines or water intrusion (milky oil). Pressure/vacuum test if contamination is found.	Lower Unit Seal Kits
Spark plugs	Inspect every 100 hours; replace annually or as needed	Set the correct gap; replace sooner if fouled or corroded.	Spark Plugs
Fuel filter / water separator	Every 100 hours or each season	Helps prevent lean running and starting issues, especially with ethanol‑blended fuel.	Fuel Filters
Water pump impeller/kit	Every 2 seasons or 200 hours (sooner for sandy/silty use)	Renew impeller; inspect wear plate and cup; replace gaskets and key.	Water Pump Impeller Rebuild Kits
Anodes (sacrificial)	Inspect every 50 hours; replace when ~50% consumed	Select the correct alloy for your water: aluminum, zinc, or magnesium.	Anodes
Thermostat & gaskets	Inspect annually; replace every 2–3 years	A sticking thermostat can cause cold‑running or overheat alarms.	Service & Maintenance Kits
Propeller, cotter/nut	Inspect each outing; replace if bent, chipped, or with a slipping hub	Carry a spare and verify diameter/pitch for your hull and load.	Propellers

*Severe duty (commercial use, frequent trolling, sandy/silty water) may require shorter intervals.

Frequently Used Parts Categories

Routine Service – Service & Maintenance Kits
Cooling System – Water Pump Impeller Rebuild Kits
Fuel System – Fuel Filters
Ignition / Electrical – Spark Plugs
Lower Unit & Seals – Lower Unit Seal Kits
Propulsion – Propellers
Corrosion Protection – Anodes

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale stream or overheat alarm	Inspect intake screens for debris, verify impeller condition, and confirm thermostat operation.	Water pump kit, intake screen, thermostat, gaskets.
Hard starting / rough idle	Check fuel freshness, filter condition, spark plug gap, and idle speed; for EFI models, verify battery voltage.	Fuel filter, spark plugs, fuel pump, battery cables.
Poor acceleration / power loss	Inspect propeller for damage and correct pitch; look for restricted fuel flow or fouled plugs.	Propeller, spark plugs, fuel filter, fuel pump.
Gearcase noise or milky gear oil	Check for fishing line on the prop shaft; change gear oil and pressure/vacuum test the gearcase if contamination is found.	Lower unit seal kit, prop shaft seals, drain/fill gaskets.

FAQs

Are parts interchangeable between 15HP and 20HP models?

Many wear items are shared across the 15–20HP 4‑stroke platform, but output and rigging differences can affect certain components. Always confirm with your model/serial and shaft length.

When should I replace the water pump impeller?

Under typical recreational use, replace every two seasons or ~200 hours. In sandy, silty, or shallow environments, inspect more often and shorten the interval.

How often should gear oil be changed?

At least annually or every 100 hours. If water intrusion or metal debris is present, service immediately and pressure/vacuum test the gearcase to locate failed seals.

What information helps confirm part compatibility?

Provide a clear photo of the serial plate, model designation, shaft length (S/L), starting method (manual/electric), and photos/measurements of the part you are replacing.

Ready to browse parts by horsepower, year, and model? Start with our service essentials and narrow down using the collection filters.

Shop Service & Maintenance Kits

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.