GM/YM Series Shaftdrive 9-29mhp

Sailing Engines

With the largest displacement and smallest dimensions in their class, these thoroughbred workhorses provide sure-fire auxiliary power for sailboats and durable primary power for small motorboats.

Engine Model

  • 1GM10 9.0mhp @ 3600rpm
  • 2YM15 14.0mhp @ 3600rpm
  • 3YM20 21mhp @ 3600rpm
  • 3YM30AE 29mhp @ 3200rpm

Gear Option

  • KM2P-1 Ratio – 2.21 / 2.62 / 3.22

1GM – More power, same size

Yachtsmen looking for extra power without extra size and weight can find it in Yanmar’s new 1GM10 diesel engine. Yanmar have up-powered their popular 1GM model by 20% to re-create its trusty performance at a higher 6.7kW, with negligible change in size, weight and shape. Its only gain is a heftier flywheel to maintain smooth running and easy starting.

YM Series

The naturally aspirated new generation YM series continues the Yanmar tradition of providing boaters with superior technology – quiet, compact power to be relied upon.

The latest lightweight propulsion developments from the diesel leader Yanmar are the all new 2YM15, 3YM20 and 3YM30AE models. The 3YM20 and 3YM30AE were designed as a direct upgrade for the legendary 2GM20 and 3GM30E models they replace. The new 2YM15 is an additional model to what is recognized already as the most complete line up of marine engines in the business. With the added benefit of simplified maintenance due to the new location of the sea-water pump and all other service points being together near the engine front these units, no doubt are already on track to be recognized as the best-in-class auxiliary power for sailboats and tough, reliable primary power for small motor craft.

Best-in-class diesel power

More and less: With more displacement, more torque, more amps, yet even quieter, with less smoke than ever, EPA Tier 2 emission regulations and BSO/SAV stage 2 compliant. The flat power curve allows you to choose the propeller size to best match your application.

The same:

For ease of installation and for repowering, these latest 3 cylinder models are the same size as their predecessors, with similar footprints.

All new:

Completely re-designed cylinder block and indirect combustion system for optimised performance and maximum economy. New compact control panel, new injection pump, and new electric stop solenoid.



  • Flexible engine mounts x 4


  • Exhaust water mixing elbow, L-type

Starting & Stopping

  • Engine stop cable (manual) only for GM Series
  • Engine stop solenoid for YM Series

Electrical and Instrumentation

  • Alternator, 12V
    1GM – 35A
    2YM – 125A
    3YM – 125A
  • New B20  instrument panel (Medallion type)
  • Extension wire harness (GM- 3 mtrs/YM – 6 mtrs)

Front belt cover(guard) for YM Series

Optional Accessories


  • Propeller shaft half coupling (slit type)
  • Propeller shaft half coupling (taper type)
  • Propeller Shaft half coupling (pilot bore)


  • Kingston cock/sea water filter

Electrical and Instrumentation

  • Electric type bilge pump, 12V
  • Battery Switch


  • Push-pull type remote control cable 2 pcs/unit (MORSE:33C)
  • Side-mount type single control head (MORSE:MV)
  • Top-mount type single control head (MORSE:MT3)


  • Spare parts kit