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6LT Series

6LT Series Common Rail Engine


500 mhp
367 kW
2530 rpm


580 mhp
 426 kW
2530 rpm


640 mhp
 470 kW
2530 rpm


  • Suitable for large superyacht tenders, planing and semi-planing motor yachts up to 55ft, as well as fast boats, and light-duty commercial vessels such as workboats, RIBs, fast rescue boats, and coast guard/military craft
  • High power, low weight, and compact installation creating a high power density of 74 mhp/L liter for the 640 mhp model
  • Controlled by YANMAR VC20 Vessel Control System
  • Complements the largest common rail recreational and light-duty commercial diesel engine line-up on the market
  • Exceeds EPA Tier 3 and EU RCD Stage 2 emissions regulations

Compact And Powerful

Expanding YANMAR’s renowned common rail range up to an output high of 640 mhp, the 6LT is a compact and light-weight diesel engine that is an ideal solution for planing and semi-planing hulls, and fast boats, with inboard propulsion systems, suiting a range of recreational and light-duty commercial applications.

The powerful 3-model line-up, offering similar benefits to the sister 6LF powerboat series, adds higher horsepower engines to the YANMAR brand portfolio, creating the largest common rail, electronically-managed marine diesel line-up in the industry.

The 6LT series features YANMAR’s next-generation VC20 vessel control system for enhanced onboard comfort and an easier overall boating experience.

Meeting EPA Tier 3 and EU RCD Stage 2 emissions regulations, the 6LT offers leading fuel economy and also provides a wide range of fuel compatibility to meet requirements for various government service applications.

The 6LT has been customized with YANMAR’s proprietary fuel mapping and a larger mixing elbow for reliable and consistent output performance. It is custom engineered to offer direct connectivity to NMEA and J1939 CAN-bus networks.

Available as a complete package, the engine comes available with a number of standard and optional features, including single- and 2-pole installation, various ZF gears, and custom secondary alternator options to meet nearly any complex application.


  • Available in 3 output models – 500, 580, 640 mhp
  • A proven solution for jet and shaft drives
  • Controlled electronically by YANMAR VC20 Vessel Control System, for 3 engines with up to 4 stations
  • Custom YANMAR fuel mapping and mixing elbow & bracket for reliable performance output
  • Custom YANMAR gearbox configuration to reduce vibration and increase efficiency
  • Custom engine packaging for efficient installation
  • Certified for recreational and light-duty commercial applications*
  • See all certifications details[JR1] 

*Please note, the 6LT640 is not EPA Commercial certified.

Featured Applications

Common Rail Technology

YANMAR uses advanced common rail technology to achieve the most efficient engines in their class. Learn more about this technology and Yanmar common rail engines.

5X Best In Class

YANMAR common rail marine engines set global standards in performance, efficiency, and endurance. Learn more about how YANMAR achieves 5x Best-in-Class.


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