Yamaha LF250USB 250HP – DEC 30″ Shaft Counter Rotationin Gray

Yamaha LF250USB 250HP Integrated Counter

The Yamaha LF250USB pairs a 4.2L 24-valve DOHC V6 with counter-rotation gearing and integrated steering, at 553 lbs dry — a strong power-to-weight ratio for modern offshore vessels. The 30-inch ultra-long shaft is built for boats in Mulmarine’s marine outboard solutions lineup that need neutralized steering torque and integrated digital electric steering.

Peak output holds through the 5000-6000 RPM band, using Integrated Digital Electric Steering (DES) and Helm Master EX compatibility. The 1.75:1 gear ratio gives the mechanical leverage to turn larger propellers for immediate hull thrust. US offshore boaters get better steering authority and stable tracking in both open sea and protected harbor conditions.

Technical Specifications of Yamaha LF250USB

• The V6 4.2L DOHC architecture delivers 250 horsepower with strong volumetric efficiency.
• The 251 kg build runs a 30-inch ultra-long shaft for offshore transom configurations.
• Integrated Digital Electric Steering (DES) delivers effortless handling and precise control at any speed.
• The counter-rotation (left-hand) gearcase balances steering torque in multi-engine installs.
• Digital Electronic Control (DEC) with Helm Master EX compatibility keeps helm management smooth.
• The 50-70 Amp alternator output keeps navigation radar and digital sonar powered.
• Coverage comes from a 3-year limited factory warranty and Japanese build standards.

V6 Integrated Command

The LF250USB uses a 24-valve V6 configuration to maximize air intake and torque, delivering hole-shot acceleration even under heavy loads and chop.

DES Technology Precision

Integrated Digital Electric Steering (DES) gives a smooth, responsive feel without external hydraulic lines, keeping the bilge clean and reducing operator fatigue on long tournament days.

Offshore Shaft Propulsion

The 30-inch ultra-long shaft is calibrated for modern offshore transom dimensions, preventing propeller aeration in following seas.

Helm Master EX Integration

This engine is fully compatible with Yamaha Helm Master EX for advanced positioning and joystick control, allowing precise movement in tight quarters.

Routine Maintenance Protocol

This digital V6 runs high-quality sacrificial anodes to keep galvanic corrosion in check in saltwater coastal environments. Pro Tip: flush the internal cooling passages with fresh water after every launch to maintain cooling system integrity.