This manual provides essential service information for Mercury Mercruiser Marine Engines, specifically focusing on the Gen III Cool Fuel module. Designed for servicing and repair, this supplement addresses the Gen III Cool Fuel module, fuel system, and cooling system components. It details the engineering and reliability inherent in Mercury Mercruiser products, offering comprehensive guidance for maintaining optimal performance. This workshop service repair manual supplement covers the Gen III Cool Fuel module for all models, along with troubleshooting and repair procedures for the fuel system and cooling system. It includes diagrams for fuel flow and coolant/water flow, and details maintenance procedures. This English-language manual is intended to assist owners, mechanics, and technicians in understanding and performing necessary service and repair operations on their Mercury Mercruiser marine engines.