🔍 Key Concepts

• Diesel engine air-fuel ratio and how lack of air affects combustion • Relationship between air intake, power output, and engine speed • Typical causes of knocking, surging, or overspeed in diesel engines

💭 Think About

• Think about what happens to combustion when there is not enough air but the same amount of fuel is being injected. • Which of the listed symptoms is most likely tied to too little oxygen in the cylinders rather than to fuel system or governor problems? • Consider which options (knocking, surging, overspeed, low speed) usually come from fuel or governor issues, not air restriction.

✅ Before You Answer

• Verify which effect is directly linked to reduced power output from incomplete combustion. • Check which symptoms (knocking, surging, overspeed) are more commonly associated with fuel timing, fuel quality, or governor malfunctions, not air restriction. • Confirm which choice best matches a general loss of engine breathing capacity (restricted intake).