After testing your medium-speed engine's exhaust valve springs you find one with a spring constant that is lower than specified by design and a length that is reduced in length from that specified by design. What is the recommended course of action?

Correct Answer: Option D — Replace spring and check the valves cam and follower for marring caused by bounce.

A weakened valve spring with a reduced spring constant and shortened free length suffers from fatigue and loss of elasticity. It must be replaced immediately, along with inspecting the cam and follower for pitting or marring caused by dynamic valve bounce.