50-58788A3 Aftermarket Mercury Mariner Outboard Starter Motor | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket Mercury/Mariner outboard starter motor - Part Number: 50-58788A3

A ten-tooth 12-volt starter for early Mercury and Mariner inline four-cylinder two-stroke outboards. It is principally used on Model 650, 800 and 850 engines from the late 1960s and 1970s. It is an outboard starter, not a MerCruiser sterndrive part.

This historical Mercury starter is no longer available as a new OEM assembly, making a correctly matched marine aftermarket replacement the normal service option.

⚙️ Key Features

• 12V outboard starter motor

• Ten-tooth starter drive

• Suitable for early Mercury inline-four flywheel arrangements

• Complete replacement motor and drive assembly

• Marine-duty corrosion-resistant construction

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 50-58788A3 → Supersedes 50-58788

• OEM assembly is no longer serviced as a new Mercury part

OEM / Related Numbers:

• Mercury: 50-58788A3

• Mercury: 50-58788

• Mercury: 50-57465A1

• Mercury: 50-57867A1

• Mercury: 50-64975

• Mercury: 50-72467

Aftermarket / Verified Equivalents:

• Sierra: 18-5636

• ARCO Marine: 5377

• Mallory: 9-15009

• Mallory: 9-15029

🚤 Compatibility

Commonly used on:

• Early Mercury and Mariner inline four-cylinder two-stroke outboards

Typically suits:

• Engine models:

• Mercury 650 / 65HP four-cylinder

• Mercury 800 / 80HP four-cylinder

• Mercury 850 / 85HP four-cylinder

• Corresponding Mariner models fitted with the same ten-tooth starter

• HP Range: 65HP-85HP

• Engine Type: Inline four-cylinder carburetted two-stroke outboard

• Year Range: Approximately 1969-1977

• Serial Guidance:

• 650: commonly serial 2803562-3293183

• 800/80: commonly serial 2559001-3493912

• 850: commonly serial 3493913-4366801, with additional international serial groups

🔌 Function

The starter drives the flywheel during engine start-up and disengages automatically once the engine fires.

Common signs of failure:

• No starter response

• Slow cranking or excessive current draw

• Starter spins but does not engage

• Grinding caused by damaged pinion or ring-gear teeth

• Intermittent operation from worn brushes or bushings

📦 Condition

• Brand-new aftermarket starter motor

• Supplied as a complete ten-tooth assembly

• Verify the original starter number and flywheel engagement before installation