BASIC ENGINE KNOWLEDGE

You know your way around marine engines? This captain’s test will gauge your basic marine engine knowledge. Let’s see how much you know. — John Tiger

1. What is the main difference between a four-stroke engine and a two-stroke engine?

A. A four-stroke is faster than a twostroke.

B. A four-stroke uses mechanical valves and a camshaft to control the intake charge, where a two-stroke uses reed valves and piston ports for the same function.

C. A two-stroke makes power every revolution of the crankshaft, where a four-stroke makes power with every two revolutions of the crankshaft.

D. A four-stroke is more expensive than a two-stroke.

E. None of the above

F. B and C

2. What does DFI mean relative to an engine?

A. Don’t Forget It

B. A new type of ignition system on “clean” outboard engines and sterndrives

C. Different Fuel & Ignition

D. Direct Fuel Injection

E. None of the above

3. What does the term I-6 typically mean when referring to a marine engine?

A. Nothing, the term has no significance. B. Ignition Six C. Inline Six D. None of the above

4. What is a catalytic converter, what does it do, and why is it installed on modern inboard and sterndrive gasoline engines?

A. It helps keep the engine exhaust clean (reduces emissions).

B. It’s required by law, similar to automobiles.

C. A device integrated into the exhaust system, with a substrate inside that converts toxic gases and pollutants into less environmentally damaging emissions.

D. All of the above

E. A and B

5. Why are more boat manufacturers introducing hulls designed, built and equipped with multiple outboards instead of using sterndrives?

A. Outboards have recently grown to become larger and more powerful, and at the same time they are still lighter than inboards and sterndrives.

B. Outboards are more easily replaceable if necessary; simply unbolt the old one and replace with the new one.

C. Sterndrives and inboards are obsolete.

D. None of the above

E. A and B

6. When talking to your mechanic, what is the difference between these statements: 1) “My engine won’t start.” 2) “My engine won’t turn over.” 3) “My engine won’t fire.”

A. There is no difference; they all mean the same thing.

B. “Won’t start” could mean either 2 or 3.

C. No. 2 means the engine starter won’t engage and crank the engine.

D. No. 3 means the starter cranks the engine, but it won’t start and run.

E. None of the above

F. B, C and D

1. F. The latest four-strokes are no more expensive than two strokes, and top speeds are very comparable.

2. D. Direct Fuel Injection, used (for example) on Evinrude E-Tec outboards.

3. C. Inline Six, referring to the cylinder configuration of the engine block.

4. D.

5. E.

6. F.

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