MTC MTC Steering & Propulsion Systems 2

Question 1

What is the correct torque sequence when installing a propeller on a tapered shaft with a keyway?

Accepted Answer

Install propeller, add key, install nut, torque to spec, install cotter pin or locking device

Answer

The woodruff key must be seated before the propeller, the nut torqued to the manufacturer's specification, and a cotter pin or locking tab installed to prevent the nut from backing off.

Question 2

When selecting a replacement propeller, which two specifications are MOST critical to match for correct engine loading?

Accepted Answer

Diameter and pitch

Answer

Diameter determines thrust and RPM band while pitch controls the theoretical advance per revolution; together they define the propeller's load on the engine and must match the power and application.

Question 3

A boat experiences constant pulling to one side at cruise speed with no steering input. What is the MOST likely cause?

Accepted Answer

Propeller torque effect or a bent/damaged propeller blade

Answer

A bent or damaged propeller blade creates an asymmetric thrust that causes the vessel to veer, and propeller torque effect (prop walk) is inherent in single-engine vessels without compensation.

Question 4

What is the purpose of the 'anti-ventilation plate' (cavitation plate) located above a propeller on an outboard motor?

Accepted Answer

To prevent surface air from being drawn down to the propeller, which would cause loss of thrust

Answer

The anti-ventilation plate creates a pressure barrier that separates the water surface from the propeller, preventing air ingestion that would cause the propeller to 'ventilate' and lose thrust.

Question 5

How is engine trim angle measured on an outboard or sterndrive application?

Accepted Answer

As the angle of the drive unit relative to vertical (or the transom)

Answer

Trim angle describes how far the lower unit is tilted in or out relative to the transom; negative (in) trim digs the bow down while positive (out) trim raises the bow and reduces drag at speed.

(MTC) Marine Technician Certification Practice Test

(MTC) Marine Technician Certification Practice Test

MTC MTC Steering & Propulsion Systems 2