What is the purpose of Automatic Compression Release (ACR)?

The purpose of Automatic Compression Release (ACR) is primarily to decrease compression for easier manual starting of an engine. ACR allows the engine to reduce its compression during startup, which makes it less strenuous for the operator to pull the starter cord or crank the engine manually. This reduction in compression means that the engine components do not resist as much during the starting process, thereby facilitating a smoother and easier starting experience, especially in portable generators or small engines.

This mechanism is beneficial in various applications, particularly in outdoor power equipment where ease of operation is critical. Once the engine starts and reaches a certain speed, the ACR mechanism disengages, allowing for normal compression and optimal engine performance during operation. The focus here is on facilitating the starting process rather than directly affecting efficiency or combustion directly.