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Engine & Fuel

Engine Overview

Specification Details
Make / Model Yanmar diesel, 4JH57 series
Power ~57 hp
Drive Saildrive
Propeller 3-blade folding
Throttle Electronic digital — at both helm stations
Max RPM 2,300
Fuel tank ~210 L diesel
Burn rate ~1.5 L/hr at 5 kn
Cruising range ~700 nm at 5 kn
Reserve rule Never go below 30 L

Starting the Engine

  1. Ensure all electrical panels are on and the battery isolator is in the correct position
  2. Wait for the Yanmar instrument panel to fully boot before starting — the display shows all warning lights, they should extinguish as the system self-tests
  3. Check oil level before long passages (dipstick in engine bay — lift saloon floor panel)
  4. Press the start button at the helm
  5. Do not crank for more than 10 seconds continuously — if it doesn't fire, investigate

After starting: Check for raw water exhaust (water should flow from the stern exhaust within a few seconds). If no water after 10–15 seconds, stop the engine and check the raw-water seacock and impeller.


Throttle & Gear

The electronic digital throttle controls both throttle and gear selection. The lever works the same at both helm stations — only one can be active at a time (helm station selection is made at the panel).

RPM Approximate speed
1,500 ~3.5–4 kn
1,800 ~4.5–5 kn (economic cruise)
2,000 ~5.5–6 kn
2,300 (max) ~6.5 kn

Bow Thruster

24V electric, retractable — Quick BTR185.

Use in short bursts only

Maximum 6-second bursts. Continuous use will overheat and trip the thermal cutout. Wait 30+ seconds between bursts. If it cuts out, wait 5–10 minutes before trying again.

Control is via the joystick at the helm stations and/or the dedicated panel inside.


Stern Thruster

24V electric, retractable — same family as bow thruster. Same burst-use rules apply.


Fuelling

  • Fuel type: Diesel only
  • Fill point: Starboard side deck (labelled)
  • Fill slowly to avoid spills — the tank breather is nearby
  • Tank: ~210 L — fill up before any overnight passage or if below ~60 L

Engine Maintenance Checks

Check Frequency
Engine oil level Before every long passage
Raw-water impeller Annually (or if overheating alarm sounds)
Fuel filter (primary) Every 250 hours or annually
Zincs on saildrive Every haul-out
Coolant level Monthly

Overheating alarm: Stop the engine immediately. Most likely cause is a failed raw-water impeller or blocked seacock. Do not restart until the cause is identified.


Raw-Water System

The engine is cooled by a raw-water impeller that draws seawater in through a hull seacock (below the waterline, engine bay). The seacock must be open whenever the engine is running.

If the impeller fails (typically every 1–2 seasons), the engine will overheat within minutes. Spares are kept in the engine bay spares kit.


Manuals