Question 24Motor Plants - 1st Asst/Chief

The correct answer is B) fuel pumps. The main camshaft in the illustrated engine controls the timing of the fuel pumps. The camshaft is responsible for opening and closing the fuel pumps at the proper times to deliver fuel to the engine cylinders. The camshaft does not directly control the opening and closing of the exhaust valves (option A) or intake valves (option C), as those are typically controlled by separate camshafts or rockers. Option D is incorrect because the main camshaft does not control all of those components, only the fuel pumps.