This manual provides comprehensive service and repair information for the Doosan L136, L136T, L136TI, and L086TI marine diesel engines. These engines are engineered for robust performance and reliability in demanding marine applications. This document details all necessary procedures to ensure the optimal functioning and longevity of your Doosan marine diesel engine. The scope of this manual encompasses all repair, servicing, and troubleshooting procedures. It is designed to be an indispensable resource for owners, professional mechanics, and technicians. With hundreds of pages of detailed instructions, photographs, and exploded diagrams, this manual guides users through every task, ensuring correct completion and effective maintenance of the specified Doosan engine models.