MTC MTC Steering & Propulsion Systems

Question 1

What is the most common cause of excessive play (looseness) in a mechanical boat steering system?

Accepted Answer

Worn or stretched steering cable or loose helm connections

Answer

Steering cables stretch and wear over time, and loose connections at the helm or tiller arm create play that reduces steering precision and control.

Question 2

When bleeding a hydraulic steering system on a marine vessel, what is the correct procedure?

Accepted Answer

Attach a vacuum pump to the fill port while turning the wheel lock-to-lock

Answer

Using a vacuum pump at the fill port while cycling the steering wheel lock-to-lock draws air bubbles out of the system and allows clean fluid to fill all passages.

Question 3

What does 'propeller cavitation' mean in the context of marine propulsion?

Accepted Answer

Formation and collapse of vapor bubbles on propeller blades causing pitting and loss of thrust

Answer

Cavitation occurs when low pressure on the propeller blade face causes water to vaporize; when these bubbles collapse, they create micro-jets that erode the blade surface and reduce efficiency.

Question 4

What is the purpose of a trim tab on an outboard motor or sterndrive?

Accepted Answer

To control the running angle of the vessel to optimize performance and fuel efficiency

Answer

Trim tabs (on the cavitation plate or transom) adjust the bow-up or bow-down attitude of the vessel, allowing the hull to run at its most efficient planing angle.

Question 5

When inspecting a propeller shaft for runout, what tool does a marine technician use?

Accepted Answer

Dial indicator (dial gauge)

Answer

A dial indicator measures the total indicator runout (TIR) of the shaft as it is rotated, revealing bends or eccentricity that would cause vibration and bearing wear.

(MTC) Marine Technician Certification Practice Test

(MTC) Marine Technician Certification Practice Test

MTC MTC Steering & Propulsion Systems