6LY-CR Series Shaft Drive 400-440mhp

Power Boat Engines

Yanmar 6LY-CR Series Marine Diesel Engine 400 – 440MHP


  • 6LY400 400MHP @3300RPM
  • 6LY440 440MHP @3300RPM


  • KMH61A2 (Down Angle 8 degree) Ratio 1.55 / 2.04 / 2.43
  • KMH61V2 (Integral 12 Degree Vee Drive) 1.24 / 1.49 / 1.98 / 2.43
  • ZF280-1 (Parallel) 1.00 / 1.056 / 1.139 / 1.214 / 1.300 / 1.514 / 2.00 / 2.48

High Performance Straight Six

YANMAR’s fourth-generation 6LY-CR marine diesel series builds on the virtues of its classic six-cylinder forerunners, advancing efficiency and lowering emissions.

The new engine takes what was a very accomplished and highly popular power unit to a higher level. Like all YANMAR marine engines, it was designed expressly for marine duty.

After decades of distinguished service 6LY engines are still regarded as some of the best in the world for cruising and workboat duty. In has been transfigured into the 6LY-CR and is set to continue this tradition. Its small footprint, low height and narrow width will make it attractive for installation in new craft with ever-tighter engine room space. Its high power density in an ultra-compact package will also make it an engine of choice for replacement not only of earlier YANMAR units but also larger and heavier engines of similar output.


The 6LY-CR has common-rail fuel injection in place of single mechanical direct injectors and is rated for leisure marine and light duty commercial workboat applications.

There’s new pipe work to handle the higher pressures of the Denso CR system, as well as a new 24-valve cylinder head, along with redesigned inlet and exhaust manifold to assist engine breathing.

It’s unique features are:

  • 4th generation YANMAR 6LY engine
  • Purpose-built marine engine
  • Legendary YANMAR reliability
  • Complies with US Tier 3 and EU RCD 2 emissions limits
  • YANMAR’s VC10 Electronic “fly by wire” control and instrumentation.

Electronic Integation

This latest incarnation has taken the engine into a new era of mechanical and digital sophistication. YANMAR have completely re-engineered the fuel induction and aspiration systems; all functions are now managed by state-of-the-art electronic precision for better all-round performance.

YANMAR have replaced single injectors with a high-pressure common-rail fuel system to deliver exceptional finely atomised fuel to the cylinders for better power-to-weight performance, fuel economy and smooth running.

Fingertip controllability

For the ultimate in easy and precise boat control, YANMAR offers the latest VC10 ‘fly-by-wire’ vessel control system to give precision gear changing and throttle adjustment with perfect ‘feel’. And with the joystick control option as part of a fully-integrated YANMAR engine and controls package, docking is also really easy.

Controls & Instrumentation

Single and dual-lever control heads have push-buttons for functional selection. Operations are precisely monitored on 3.5-inch robust IP66-rated display screens with IP66 waterproof rating and with full diagnostic capabilities plus UV-protection, anti-dazzle coating and anti-fog ventilation.

For maximum operational security, two parallel CAN bus networks separate engine and monitoring functions. YANMAR’s J1939 control bus is dedicated to the engine and drive control system while GPS, chart plotter and monitoring displays are handled by NMEA2000 data bus so that, in the unlikely event of J1939 failure, the system automatically switches to a pull-out back-up panel.


  • Engine Displacement: 5.813 litres
  • Bore & Stroke: 106mm x 110mm
  • Combustion System: Direct Injection with Denso Common-Rail system
  • Dry weight withour gear: 585kg
  • Environmental: EU: RCD Tier 2 / US: EPA Tier 3 / IMO: Tier 2


  • 2-pole 12 Volt electric system
  • Alternator 12V-125 amp
  • Exhaust/Water mixing elbow
  • Mounting Brackets
  • Flexible engine mounts


  • YANMAR CAN-bus control system
  • Multi-function colour display
  • NMEA 2000 or J1939 gauge output
  • Switch Panel (start – stop)
  • Back up panel


  • Fuel water separator
  • High riser mixing elbow
  • Solas Kit including certificates
  • 24 volt secondary alternator


  • Electronic CAN-bus control-head
  • External wire harness
  • NMEA 2000 gauges
  • Second or Third station controls and instruments

VC10 offers operational modes for single and twin-inboard or sterndrive installations. All are designed for easy serviceability and are readily expandable to allow owners to extend monitoring capabilities at any time.

Yanmar JC control system for 6LY marine diesel engine