This workshop service repair manual provides comprehensive information for JLO engines, covering both single-cylinder and twin-cylinder models. It details repair procedures for a wide range of specific engine models, including the L-99, L-230, L-227, L-295, R-295, L-297, L-300, L-340 for single-cylinder configurations, and LR-340/2, LR-399/2, LR-440/2, LS-600/2 for twin-cylinder applications. This manual is designed to assist owners and mechanics in understanding and maintaining these engines. The purpose of this manual is to serve as a complete guide for engine service and repair. It includes step-by-step repair procedures, troubleshooting guides, detailed technical specifications, and wiring diagrams. Furthermore, it covers operating instructions, carburetor and ignition system information, exhaust system details, assembly and disassembly processes, engine and recoil system coverage, timing instructions, and warranty information. With hundreds of photos and illustrations, this English-language manual is an invaluable resource for both do-it-yourself enthusiasts and experienced mechanics.