Question 1

This whole cascade began because the impeller failed without warning and the fuel filter was not changed to proper procedure. What pre-departure engine checks would have caught both issues?

Accepted Answer

Check engine oil level (dipstick); check raw water strainer is clear; check coolant level; look at exhaust water flow on startup; inspect V-belt tension and condition; verify fuel level in tank; check filter bowls for contamination — and follow a written engine log to track impeller/filter service intervals Pre-departure engine check (WOBBLE or BOAT mnemonic used by some instructors): Water (coolant), Oil, Battery/belts, Look at exhaust water, Electrics. Add: fuel filter bowl inspection (water contamination visible), raw water strainer check, confirm seacock open. Impeller service: typically 200 hours or annually — keep a written log. A 5-minute check prevents a 2-hour breakdown 400m from a harbour.

Question 2

You turn the key. No cranking sound at all — complete silence. What is the most likely fault category and what do you check first?

Accepted Answer

Electrical: check battery voltage (battery monitor or multimeter); check main battery isolator switch is ON and set to the correct bank; check the engine battery is not flat; check the kill/stop control is in the RUN position No crank = electrical fault (unless the decompressor or stop control is engaged). Sequence: 1) Is the battery isolator ON and on the correct bank? 2) Is battery voltage above 12V (10.5V minimum for cranking)? 3) Is the kill/stop control fully in RUN? 4) Is the neutral safety switch in neutral? Do not proceed to fuel diagnosis until you have confirmed electricity is reaching the starter motor.

Question 3

The battery isolator has two banks (1 = House, 2 = Engine, BOTH). The switch is on BOTH. The voltage reads 11.8V. What does this tell you and what do you do?

Accepted Answer

11.8V is borderline for reliable starting — switch to Bank 2 (engine bank only) which may have more charge; reduce all electrical loads; try cranking on the dedicated engine bank A diesel starter motor needs high current (200–500A peak). 11.8V under no load may drop to 9–10V under cranking load on BOTH banks — below the starter's cut-out. Switch to the dedicated engine bank, turn off navigation instruments and VHF to reduce parasitic load, and crank in short bursts (10 seconds max) to avoid overheating the starter. If still no crank, check the starter solenoid wire and starter motor itself.