This manual covers the 4LH Series Marine Diesel Engine, a robust and reliable unit designed for marine propulsion. Engineered for demanding maritime environments, these diesel engines are known for their efficiency and durability, providing dependable power for a wide range of vessels. The 4LH Series represents a commitment to quality and performance, ensuring optimal operation for recreational and commercial marine applications. This comprehensive Full Service & Repair Workshop Manual provides detailed instructions for the maintenance, servicing, and troubleshooting of the 4LH Series engines. It includes hundreds of pages of information, supported by detailed photos, diagrams, and step-by-step instructions, with exploded diagrams to aid in understanding complex assemblies. This English-language resource is designed to empower owners, mechanics, and technicians with the knowledge required to keep these marine diesel engines in peak operating condition.