Question 112Motor Plants - Assistant Engineer

The correct answer is D. The indicator diagram shown in illustration MO-0029, option D, indicates the condition that should be corrected by retarding the timing and the fitting of thicker shims to the connecting rod. This is because the diagram shows a late closing of the exhaust valve, which can cause increased compression pressure and temperature, leading to reduced engine efficiency and potential engine damage. Retarding the timing and increasing the shim thickness can help correct this issue by adjusting the valve timing and reducing the compression ratio. The other options, A, B, and C, do not represent the specific condition that requires the corrective actions mentioned in the question.