50-863007A1 Aftermarket Mercruiser Starter Motor | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket MerCruiser/Volvo Penta/Marine Power GM marine starter motor - Part Number: 50-863007A1

A 12-volt permanent-magnet gear-reduction starter for selected GM-based marine petrol engines. The ignition-protected unit commonly uses an eleven-tooth pinion and staggered lower mounting pattern for a 14-inch flywheel. It is widely applied to MerCruiser V6 and V8 packages and selected 3.0L installations where the original mounting arrangement matches.

Because GM marine starters are available in straight-across, staggered, top-mount and reverse-rotation configurations, the bolt pattern, flywheel diameter, pinion count and engine rotation must all be checked.

⚙️ Key Features

• 12V permanent-magnet gear-reduction starter

• Eleven-tooth steel pinion on the applicable configuration

• SAE J1171 ignition-protected marine design

• Staggered lower mounting pattern commonly used with 14-inch flywheels

• High-torque compact replacement construction

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 50-863007A1 → Supersedes 50-806964A4

• 50-806964A4 → Supersedes 50-806964A3

OEM / Related Numbers:

• Mercury/MerCruiser: 50-863007A1

• Mercury/MerCruiser: 50-806964A4

• Mercury/MerCruiser: 50-806964A3

• Volvo Penta: 3885317

• Marine Power: 475447

Aftermarket / Verified Equivalents:

• ARCO Marine: 30470

• ARCO Marine: 30433, where mounting and pinion configuration match

• Sierra: 18-5913

• API Marine: AP-10099HD

• Recmar: REC50-863007A1

🚤 Compatibility

Commonly used on:

• GM-based MerCruiser, Volvo Penta and Marine Power petrol marine engines

Typically suits:

• Engine models:

• MerCruiser 3.0L where the staggered 14-inch-flywheel starter is specified

• MerCruiser 4.3L V6

• MerCruiser 5.0L V8

• MerCruiser 5.7L V8

• MerCruiser 6.2L V8

• Selected MerCruiser 7.4L and 8.2L packages using the same starter configuration

• Volvo Penta GM-based engines using starter 3885317

• Marine Power GM-based engines using 475447

• HP Range: Engine-package dependent

• Engine Type: GM inline-four, V6 and V8 marine petrol engine where the listed starter arrangement is fitted

• Year Range: Approximately 1990s-2010s

• Mounting/Flywheel: Commonly staggered lower bolts and 14-inch flywheel; verify against the original starter

🔌 Function

The starter cranks the flywheel while its sealed marine construction reduces the risk of fuel-vapour ignition in an enclosed engine compartment.

Common signs of failure:

• Solenoid clicks but the engine does not turn

• Slow cranking when hot

• Starter gear grinds against the ring gear

• Starter remains engaged after the engine fires

• Intermittent operation from worn contacts, brushes or armature

📦 Condition

• Brand-new aftermarket ignition-protected starter motor

• Supplied as a complete replacement assembly

• Confirm mounting pattern, flywheel diameter, pinion and engine rotation before installation