Gale Model 5D20 Outboard Motor Specs & Overview

Overview of the Gale 5D20 Outboard Motor

Gale Products, a division of Outboard Marine Corporation (OMC), earned a reputation for building simple, durable, and affordable outboard motors throughout the mid-20th century. While OMC’s flagship brands—Johnson and Evinrude—featured the latest styling refinements, Gale motors focused on mechanical reliability and utility. Many Gale powerheads were also rebadged and sold through major department stores and mail-order catalogs under brand names such as Sea King (Montgomery Ward) and Buccaneer.

The Gale Model 5D20 is a classic 5.0 HP twin-cylinder motor that strikes a perfect balance between portability and features. Equipped with a full Forward-Neutral-Reverse gearshift, a remote 6-gallon fuel tank, and a synchronized twist-grip throttle, the 5D20 provides the versatility needed for small fishing boats, rowboats, and tenders.

Key Technical Specifications

• Model: Gale 5D20
• Horsepower Rating: 5.0 HP @ 4000 RPM (O.B.C. Certified)
• Full Throttle Operating Range: 3500 – 4500 RPM
• Engine Type: 2-cylinder, 2-port, alternate firing 2-cycle powerhead
• Displacement: 8.84 cubic inches
• Bore & Stroke: 1-15/16″ Bore x 1-1/2″ Stroke
• Gearshift: Forward-Neutral-Reverse (F-N-R)
• Gear Ratio: 15:26
• Propeller: 2-blade, 8″ diameter x 7-1/4″ pitch
• Cooling System: Rubber blade combination displacement and centrifugal water pump
• Ignition: Flywheel magneto
• Carburetor: Float feed with high-speed and low-speed adjustment needles; automotive-type choke
• Speed Control: Twist-grip synchronized spark and throttle control
• Starter: Automatic rewind recoil starter
• Fuel Capacity: 6-gallon separate fuel tank (approx. 6 hours running time)
• Transom Height: Compatible with 15″ or 20″ transoms
• Weight: 55 lbs (excluding fuel tank)

Maintenance & Restoration Guidance

Restoring a Gale 5D20 is a rewarding project due to the wide availability of shared OMC service parts. To ensure safe and reliable operation on the water, pay close attention to the following areas:

• Ignition System: Access the magneto by pulling the flywheel. Inspect the high-tension coils for cracking, a standard failure point on vintage OMC magnetos. Breaker point gaps should be set to 0.020 inches, and spark plug gaps are typically set to 0.030 inches using standard Champion J6C or equivalent plugs.
• Cooling System: Never run the motor dry. Before taking a newly acquired 5D20 out on the water, drop the lower unit and replace the flexible rubber water pump impeller. Hardened or missing impeller blades will cause immediate overheating and severe engine damage.
• Carburetor & Fuel Lines: Disassemble the carburetor to clean varnish out of the metering passages. Ensure the low-speed and high-speed needle packing washers are intact to prevent vacuum leaks. Inspect all internal fuel lines and replace aged rubber hoses with ethanol-resistant fuel lines.
• Lower Unit Lubrication: Drain the gearcase oil to check for water contamination (milkiness) or metal shavings. Refill using a quality marine gear lubricant designed for mechanical gearshift lower units. Re-seal the lower unit if water ingress is detected.

2-Stroke Fuel & Oil Mixing Advice

Because the Gale 5D20 was manufactured prior to the widespread adoption of needle and roller bearings on all internal journals, it relies on a heavier oil mixture to protect its bronze wrist-pin bushings and main bearings.

Recommended Fuel Mixture: 24:1 Ratio

• Mix 1 quart (32 oz) of marine TC-W3 2-stroke outboard oil to 6 gallons of gas (or 1/2 pint of oil per gallon of gas).
• Gasoline Selection: Always use 87-octane non-ethanol (E0) gasoline whenever possible. Ethanol degrades vintage rubber carburetor diaphragms, fuel lines, and cork gaskets over time.
• Caution: Do not run modern thin mixtures like 50:1 in this engine, as lean oil ratios will lead to premature bearing wear and powerhead scoring.