Sears 4-Stroke 6-15HP Marine Engine Parts

(2 products)

This page is for Sears 4‑Stroke 6–15 HP outboard engines. Use it to find compatible parts and service information tailored to these small four‑stroke motors. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. Sears‑badged engines in this range were often Mercury‑built, so you can also browse the main Mercury collection. Scroll to the bottom of this page to start browsing parts for this engine, and remember you can use the collection’s Filter & Sort tools to narrow results by horsepower, year range, and part category.

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How to Identify Your 6–15 HP Model

Locate the serial/nameplate on the transom bracket or swivel bracket. It lists the model designation, serial number, and horsepower.
Read the model code suffixes: they often indicate shaft length (S/L/XL), starting method (manual vs electric), and control type (tiller vs remote).
For these Sears 4‑Stroke units (Mercury‑derived), 6/8/9.9 HP typically share a small‑block platform, while the 15 HP uses a larger two‑cylinder block. Serial ranges help confirm which platform you have.
Four‑stroke identifiers: look for an oil dipstick and spin‑on oil filter on the powerhead; oil service is required unlike 2‑stroke models.

Platform Overview

6–9.9 HP Small‑Block 4‑Stroke Twin

Feature	Description
Configuration	Inline‑2, carbureted 4‑stroke; compact small‑block used across 6/8/9.9 HP variants.
Common Models	Sears‑badged versions of Mercury/Tohatsu‑built 6–9.9 HP 4‑strokes (short/long shaft, tiller or remote, manual/electric start).
Advantages	Lightweight, quiet idle, excellent fuel economy for trolling and small craft.
Notes	Many routine service parts (plugs, fuel filters, impellers) interchange across 6/8/9.9 HP. Verify by serial number for exact fit.

15 HP Mid‑Block 4‑Stroke Twin

Feature	Description
Configuration	Inline‑2, carbureted 4‑stroke; larger displacement than 9.9 HP with different carburetion and gearing.
Common Models	Sears‑badged 15 HP 4‑stroke variants (short/long shaft, tiller or remote, manual/electric start).
Advantages	Stronger mid‑range torque and planing power while remaining portable.
Notes	Water pump kits and many ignition/fuel parts are shared with sibling Mercury models; jetting and some ancillaries differ. Confirm by serial.

Routine Maintenance & Service Parts

Intervals below are general guidelines for small 4‑stroke outboards. Always follow your engine’s official service manual and adjust intervals for heavy use or harsh conditions.

Item	Interval*	Remarks	Parts Link
Engine oil & filter	After first 20 hours, then every 100 hours or annually	Use FC‑W marine oil; replace spin‑on filter each oil change.	Oil Filters
Gear oil (lower unit)	Every 100 hours or annually	Inspect for water intrusion/metal; replace gaskets on drain/fill screws.	Mercury Outboard Parts
Spark plugs	Inspect every 100 hours; replace as needed (often 200 hours)	Check gap and look for fouling from rich idle or stale fuel.	Spark Plugs
Fuel filter (inline or under‑cowl)	Every 100 hours or annually	Replace more often if running ethanol fuel or seeing debris in bowl.	Fuel Filters
Water pump impeller/kit	Every 2 seasons (annually in sandy/silty water)	Restore cooling flow and protect against overheating.	Mercury Water Pump Repair Kits
Anodes (zincs)	Inspect every 50 hours; replace when 50% consumed	Choose alloy for your water (aluminum for brackish/salt, magnesium for fresh).	Anodes

Frequently Used Parts Categories

Routine Service: Service & Maintenance Kits
Cooling System: Mercury Water Pump Repair Kits
Fuel System Filtration: Fuel Filters
Fuel Delivery: Fuel Pumps
Ignition / Electrical Tune‑up: Spark Plugs
Lower Unit Sealing: Mercury Lower Unit Seal Kits
Propulsion & Performance: Propellers

Common Symptoms & Quick Checks

Symptom	Check First	Related Parts
Weak tell‑tale stream or overheat alarm	Inspect intake screens for blockage; verify impeller condition; confirm thermostat operation.	Water pump kit, intake screen, thermostat, gasket set
Poor acceleration or power loss	Check propeller for damage/hub slip; replace fuel filter; inspect plugs; look for stale or contaminated fuel.	Propeller, fuel filter, spark plugs, fuel pump
Hard starting or rough idle	Verify cold‑start enrichment/choke; check plug gap; clean carburetor idle circuits; drain old fuel.	Spark plugs, carburetor components, fuel filter
Gearcase noise or metal in gear oil	Inspect gear oil for water/metal; check prop shaft for fishing line; pressure test seals.	Lower unit seal kit, prop shaft seals, bearings

FAQs

Are parts interchangeable across Sears 6/8/9.9/15 HP models?

Many routine service items (impellers, plugs, filters) interchange across the Mercury‑derived small‑block (6–9.9 HP) and within the 15 HP mid‑block family. Carburetor and gearing differences mean some items are platform‑specific. Use your serial number to confirm.

When should I replace the water pump impeller?

Replace every two seasons under normal use, or annually if you operate in sandy/silty water or notice a weak tell‑tale stream or temperature warnings.

How often should I change lower unit gear oil?

Change every 100 hours or once per year. Inspect the drained oil; milky color indicates water intrusion and the need to service seals.

What information do you need to verify part compatibility?

Please provide the model designation, serial number, horsepower, shaft length (S/L/XL), starting method, and whether it’s tiller or remote control. Photos of the nameplate and the part needing replacement are very helpful.

Ready to find parts by horsepower, year, and model? Browse the main Mercury outboard collection for Sears‑compatible components.

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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.