RYA Diesel Engine Course Exam: Free Mock Test & Practice Questions

RYA Diesel Engine Course Exam

This exam is for sailors and motor boaters who want to become more self-sufficient and understand how to prevent and solve diesel engine problems. It certifies the holder has the awareness to carry out routine checks and basic servicing of a marine diesel engine.

Pass mark 14/20 30 minutes Real test fee £120-£150 RYA (Royal Yachting Association) How many can I get wrong?

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Free practice questions

Try 3 real RYA Diesel Engine Course Exam questions

Have a go, then reveal the worked explanation. A taster from a bank of 219 original questions — unlock for unlimited drills and full timed mocks.

Q1. What is the correct sequence of the four strokes in a standard marine diesel engine cycle?

A. Induction, Compression, Power, Exhaust
B. Power, Compression, Exhaust, Induction
C. Induction, Power, Compression, Exhaust
D. Compression, Induction, Power, Exhaust

Show answer & explanation

✓ Answer: A. Induction, Compression, Power, Exhaust

This is the fundamental operating cycle. Air is drawn in (induction), squeezed (compression), ignited by fuel (power), and then pushed out (exhaust).

Q2. What is commonly referred to as 'diesel bug'?

A. A type of insect that nests in fuel tanks
B. Corrosion caused by saltwater contamination
C. Microbial growth that thrives at the water/fuel interface
D. An air bubble trapped in the high-pressure fuel line

Show answer & explanation

✓ Answer: C. Microbial growth that thrives at the water/fuel interface

Diesel bug is a collection of bacteria and moulds that live in the water layer at the bottom of a fuel tank, feeding on the diesel and creating a damaging sludge.

Q3. A diesel engine is running consistently hotter than normal, but not yet overheating. You have confirmed good water flow from the exhaust. In an indirect system, what is a likely cause?

A. A completely failed raw water pump impeller
B. The sea strainer is fully blocked with seaweed
C. The thermostat has failed in the fully open position
D. The heat exchanger tubes are partially scaled or blocked

Show answer & explanation

✓ Answer: D. The heat exchanger tubes are partially scaled or blocked

Partial blockage or scaling inside the heat exchanger reduces its efficiency, leading to higher running temperatures even with good raw water flow.

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RYA Diesel Engine Course Exam — common questions

Frequently asked

How many questions are in the RYA Diesel Engine Course Exam?

The exam has 20 questions. Every Revision Robin mock uses the same 20-question format so your practice matches the real thing.

What is the pass mark for the RYA Diesel Engine Course Exam?

You need 14 out of 20 correct to pass, which is about 70%. Our mocks mark you against this exact threshold.

How long do you get?

The test is timed at 30 minutes. Our full mock runs on the same clock so you can practise your pacing.

Are these the real exam questions?

No. Our questions are original and written to match the current syllabus, so they give realistic practice without copying the official paper. Every answer comes with a plain-English explanation. Always confirm current rules and content with RYA (Royal Yachting Association).

How much does the official test cost?

The official RYA (Royal Yachting Association) fee is £120-£150. Revision Robin practice is separate and helps you pass first time so you only pay that fee once.