Mavimare GF350HD Hydraulic Complete Kit up to 350HP

The Mavimare GF350HD is a heavy-duty reinforced hydraulic steering system engineered for demanding marine applications.

Designed for single outboard engines up to 350 HP, or twin outboard setups up to 700 HP with counter-rotating propellers and a suitable tie bar. Built with robust marine-grade materials, the GF350HD delivers smooth, precise, and responsive steering even under high loads.

The reinforced MC350HD balanced bullhorn cylinder features a heavy-duty shaft, support brackets, and universal lever for easy compatibility with all major outboard brands (Yamaha, Mercury, Honda, Suzuki, and more).

Contents

• Helm Pump: GM2-MRA01 (7-piston design) with integrated pressure relief valve and lock valve
• Includes standard square bezel kit (Art. X.343) for flush or semi-flush mounting
• Steering Cylinder: MC350HD (reinforced heavy-duty model with universal lever, heavy-duty shaft, support brackets, and barrel)
• Hydraulic Hoses: 2 × 7.5 m (total 15 m) SAE 100 R7 5/16" (Ø 7.94 mm) with fittings pressed on one end
• Fittings: Complete set of chrome-plated brass ORB-style fittings (1 kit GTN7X10916ORB + 1 kit AC38/T916)
• Hydraulic Oil: 2 liters of Mavimare H-AP51 (equivalent to Shell Tellus T15 or ISO VG 15 hydraulic fluid)
• Accessories: Fast-connection filler tube kit (Art. X.372) for easier filling and bleeding

Specifications

• Displacement: 27 cm³ per revolution
• Number of pistons: 7
• Maximum working pressure: 60 bar (~870 PSI)
• Relief valve setting: Typically 70 bar
• Mounting: Flush or semi-flush (hole Ø78 mm standard; larger with back-mount option)
• Max tilt angle: 20° (bleed with pump horizontal or max 10° inclination recommended)
• Cylinder Type: Balanced bullhorn, frontal mount
• Bore: Ø 34 mm
• Stroke: 200 mm (some references list ~198 mm)
• Displaced volume: ~130–140 cm³ (balanced chambers)