Gale Model 25DE20 Outboard Motor Specs & Overview

The Gale 25DE20 (and its companion models in the 22DE/25DEL series) is a classic 25-horsepower outboard motor manufactured by Gale Products, a division of Outboard Marine Corporation (OMC). Renowned for producing dependable, budget-friendly, and easily serviceable marine engines, Gale supplied motors under its own Buccaneer label as well as major department store brands such as Montgomery Ward’s Sea King. Powered by a robust 35.7 cubic inch twin-cylinder engine, the 25DE20 offered excellent torque and reliability for mid-sized runabouts, utility boats, and fishing craft of its era.

Key Technical Specifications

• Model: Gale 25DE20 (25 HP Series)
• Horsepower: 25.0 HP @ 4,500 RPM (O.B.C. Certified)
• Operating RPM Range: 4,000 – 5,000 RPM
• Engine Type: 2-cylinder, 2-port, alternate firing 2-stroke
• Displacement: 35.7 cubic inches
• Bore & Stroke: 2-7/8″ Bore x 2-3/4″ Stroke
• Gear Ratio: 12:21
• Gearshift Control: Full Forward – Neutral – Reverse (F-N-R)
• Starting System: Electric starting with manual automatic rewind backup
• Ignition System: Built-in flywheel magneto
• Carburetor: Float feed with adjustable high and low-speed needle valves
• Speed Control: Synchronized spark and throttle with twist-grip control
• Cooling System: Rubber blade combination displacement and centrifugal water pump
• Propeller: 3-blade, 10-3/8″ diameter x 12-1/2″ pitch
• Fuel Capacity: 6-gallon separate pressure/remote tank
• Weight: 126 lbs. (without fuel tank)
• Recommended Transom Height: 15″ standard or 20″ long shaft setups

Maintenance & Restoration Guidelines

Restoring or maintaining a vintage Gale 25 HP motor is a straightforward process thanks to OMC’s common engineering principles and widespread parts availability. Pay close attention to these vital components during service:

Ignition System: The built-in flywheel magneto relies on dual coils, breaker points, and condensers. Original OMC/Gale green cracked coils are common failure points due to age. Replacing the coils, setting point gaps to .020″, and installing fresh spark plugs will yield a strong, consistent spark.

Cooling System: Never start the motor out of water. The rubber impeller pump located in the lower gearcase dries out and hardens over time. Always service or replace the water pump impeller before seasonal launch to prevent severe powerhead overheating.

Carburetor Rebuild: The float-feed carburetor features dual high and low-speed adjustment needles. Disassemble, soak, and blow out all internal fuel passages. Replace older non-ethanol-safe rubber or cork gaskets with modern fuel-resistant replacements to prevent leaks and lean running conditions.

Gearcase & Lower Unit: Drain the lower unit lubricant to check for water contamination (milky fluid) or metallic debris. Re-seal the gearcase if necessary and refill with fresh marine lower unit gear lube using the bottom-fill plug method to eliminate air pockets.

2-Stroke Fuel & Oil Mixture Advice

Because mid-century OMC and Gale engines use a combination of needle, roller, and bronze bushings, proper oil volume is critical to prevent engine failure. For the Gale 25DE20, the correct fuel-to-oil mix ratio is 24:1 (1 pint of oil per 3 gallons of gasoline, or 1 quart per 6-gallon tank).

Always mix fuel using high-quality TC-W3 rated 2-stroke outboard motor oil. Whenever possible, run ethanol-free marine gasoline to preserve fuel lines, float bowls, and carb seals from chemical degradation.