What Causes Low Engine RPM?

[JaylaAnn]

Idle speed being too low is not inherently caused by the machine itself, nor does it decrease during operation. It is manually adjusted, such as being set low during factory settings or when mechanics lower it during maintenance. Below are detailed explanations: 1. Idle Speed: Excessively low idle speed can lead to an overly lean carburetor mixture, making the engine prone to stalling. In severe cases, it may cause backfiring from the exhaust pipe and difficulty starting (especially in winter). However, if set too high, fuel consumption increases significantly, and the exhaust pipe may also backfire and emit black smoke. 2. Optimal Idle Speed: Prolonged overly rich mixture can lead to spark plug carbon buildup, making ignition difficult. Therefore, idle speed must be set appropriately. Generally, it should be slightly lower in summer and slightly higher in winter.