Konrad Marine 620B Stern Drive

The Konrad 620B Stern Drive is a single-propeller sterndrive for diesel commercial and military applications, also suited to medium-duty and recreational performance use. It combines Konrad's single-propeller technology with strong shafts and gears for durability.

Key features

• Oversized bearings and thicker-walled casings
• One-piece propeller shaft
• Continuous oil circulation for cool operation
• No exhaust or water pickup through the drive
• Precision-machined super alloy gears
• No cone clutch; minimal maintenance

Technical data

• Application: recreational or commercial
• Engine connection: direct or remote (jack or CV shaft)
• Gear ratios: 1.27:1, 1.45:1, 1.55:1, 1.78:1, 1.98:1
• Lubrication: full immersion, eighteen quarts with external reservoir
• Propeller diameter range: 17.25-20 in (43.8-51 cm)
• Rotation: right or left hand
• Steering angle: 50° range
• Transmission: reversing transmission required
• Transom: 13° angle nominal, 6.4-79.4 mm (1/4-3 1/8 in) thick
• Trim/lift: approx. -6° to +10° trim, twin cylinders with electro-hydraulic pump, approx. 30° total lift range

Materials

• Taper roller bearings spaced for optimum load capacity
• High-strength, heat-treated aluminium castings
• Heat-treated high-strength alloy steel gears and high-alloy steel shafts
• Large U-joint for higher load capacity and longer life

Package

• Standard supply: complete sterndrive, inner and outer transom assembly, digital trim display and trim pump, oil reservoir with low-level sensor, integrated transom-mounted trim and steering cylinders, filled with lubricant
• Required, available from Konrad: transmission, propeller, steering package, drive shafts/tail piece, bellhousing adapter, flywheel coupling, transmission oil cooler, alignment tool
• Options: dual helm kits, isolator mounts, installation tool kit, extension kits, tie bars, stand-off boxes, engineering assistance

Each application is analysed and approved by Konrad application engineers; warranty coverage depends on an assigned maintenance schedule.