MDE 3 Q5

Answer: D) Measure the clearance with the engine cold, adjust the tappets using a feeler gauge, and then recheck the clearance with the engine at top dead center of the compression stroke.
Explanation: Tappet clearance should be measured with the engine cold to ensure accurate adjustment, as the clearances can change when the engine heats up. Using a feeler gauge, you can adjust the tappets to the specified clearance, then recheck the clearance with the engine at top dead center (TDC) of the compression stroke to ensure it is correct. This ensures proper valve operation and engine performance.

Answer: C) To ensure proper valve operation, avoid excessive wear, and maintain engine performance
Explanation: Proper tappet clearance is crucial for ensuring that the engine's valves open and close at the correct times. It helps to prevent excessive wear on the valve train components, ensures efficient engine performance, and avoids potential damage to the engine. Incorrect tappet clearance can lead to poor valve operation, decreased engine efficiency, and increased wear on the components.