Gale Model 25D18 Outboard Motor Specs & Overview

Gale Products & Model Overview

Gale Products was a core division of the Outboard Marine Corporation (OMC), renowned for producing dependable, no-nonsense outboard motors throughout the mid-20th century. While OMC marketed its flagship lines under the Johnson and Evinrude brand names, Gale manufactured robust motors both under its own name and as store-brand badged models (such as Montgomery Ward’s Sea King and Goodyear’s Sea-Bee). The Gale 25 HP (Model 25D18 series) utilizes OMC’s famous 35.7 cubic-inch twin-cylinder powerhead—a design celebrated for its mechanical simplicity, high torque output, and long-term durability on vintage fishing boats and runabouts.

Key Technical Specifications

• Model: 25D18 (also covering 25DL18 / 22D17-21 series)
• Horsepower Rating: 25.0 HP @ 4,500 RPM (O.B.C. Certified)
• Full Throttle Operating Range: 4000 – 5000 RPM
• Cylinders: 2 (Alternate firing, 2-port, 2-cycle)
• Bore and Stroke: 2-7/8″ Bore x 2-3/4″ Stroke
• Displacement: 35.7 cubic inches
• Gear Ratio: 12:21
• Gearshift: Full Forward-Neutral-Reverse (F-N-R)
• Carburetor: Float feed with high-speed and low-speed adjustable needle valves
• Speed Control: Twist-grip control with synchronized spark advance and throttle
• Ignition: Built-in high-tension flywheel magneto
• Cooling System: Combination displacement and centrifugal water pump with rubber blade impeller
• Propeller: 3-blade, 10-3/8″ diameter x 12-1/2″ pitch
• Starting: Automatic rewind manual starter
• Fuel Tank Capacity: 6-gallon separate remote fuel tank
• Weight: 115 lbs. (dry, without fuel tank)
• Transom Height Compatibility: 15″ standard or 20″ long shaft (L-models)

2-Stroke Fuel Mix & Lubrication Advice

Due to the needle and roller bearing construction used in OMC’s 35.7 cubic-inch powerheads, the standard recommended fuel-to-oil mix ratio for the Gale 25 HP motor is 24:1 (1 quart of oil per 6 gallons of gasoline, or 16 oz. of oil per 3 gallons of gasoline).

Always use a quality TC-W3 certified two-stroke marine oil mixed with fresh regular unleaded gasoline. Avoid standard automotive motor oil, which lacks the anti-scuff and low-ash additives required for water-cooled vintage outboards. Additionally, try to source ethanol-free gasoline whenever possible; ethanol absorbs moisture and accelerates the degradation of rubber fuel lines, carburetor packing washers, and fuel pump diaphragms in classic marine engines.

Restoration, Maintenance & Service Tips

• Ignition System Service: The motor uses the classic OMC Universal Magneto beneath the flywheel. When inspecting or restoring the ignition, replace aged ignition coils (which tend to crack over time), service or replace the breaker points (set spark plug gap to 0.030″ and point gap to 0.020″), and install fresh condensers.
• Cooling System Care: Never run this outboard dry. The combination rubber impeller inside the lower unit housing must be replaced periodically. If the motor has sat idle for several years, replace the impeller before your first water test to prevent powerhead overheating.
• Carburetor Tuning: The dual-adjustment carburetor allows fine-tuning for both low-speed idling and high-speed running. Initial setup typically starts at 1-1/2 turns out from lightly seated on the high-speed needle and 1-1/4 turns out on the low-speed needle. Adjust under load while the motor is in the water and at normal operating temperature.
• Gearcase Maintenance: Inspect the lower unit lubricant before and after every boating season. Refill using specialized Marine SAE 80W-90 gear lubricant. If water or milky fluid is found upon draining, replace the prop shaft, drive shaft, and shift rod seals to keep water out of the gear housing.