The component referred to as "a cocoon," with code number N73114, is likely a protective cover or insulating enclosure within the ASL25 diesel engine system. Its primary function is to shield delicate components from heat, mechanical damage, or environmental exposure—particularly in high-temperature or high-vibration zones. This type of cover helps maintain optimal operating conditions by minimizing thermal loss, preventing contamination, and improving safety for service personnel. Whether it encloses pipework, wiring, or other engine assemblies, the cocoon contributes to engine longevity, operational stability, and simplified maintenance.