Seamanship — Fuel & Engine Practice Questions

A. A type of insect that occasionally gets into fuel filler caps

B. A microbial contamination (bacteria and fungi) that grows at the interface between diesel and any water sitting at the bottom of the tank — it thrives especially in tanks that sit mostly full and undisturbed for long periods, and the resulting sludge can clog fuel filters and starve the engine, often at the worst possible moment

C. A manufacturing defect specific to certain diesel engine brands

D. A problem that only affects petrol engines, never diesel

A. The engine oil colour, since oil colour alone reliably indicates overheating causes

B. The raw water intake and impeller — a blocked intake strainer, an airlock, or a failed/worn impeller all stop or reduce the flow of cooling seawater through the engine, and this is one of the most frequent overheating causes on small-craft diesels

C. The colour of the exhaust smoke, which is unrelated to cooling in any way

D. The battery voltage, since batteries directly control engine temperature

A. Bleeding is a cosmetic step and has no real effect on engine starting

B. Air gets introduced into the fuel lines during a filter change, and diesel engines can't tolerate air in the fuel system the way petrol engines can — bleeding purges that trapped air out through the system's bleed points so fuel, not air, reaches the injectors

C. Bleeding is only necessary on engines older than 10 years

D. Bleeding refers to draining the engine oil, not the fuel system