1986 Yamaha YZ125S Service Manual

Inside the 1986 Yamaha YZ125S Service Manual

• Covers 1986 Yamaha YZ125S competition motorcycles, featuring detailed technical data for the 125cc liquid-cooled 2-stroke engine and MonoCross suspension system
• Official Yamaha publication P/N LIT-11626-05-13, 1st Edition August 1985
• Contains 100 pages of technical specifications, exploded-view diagrams, and maintenance tables for chassis and engine components
• Delivered as a direct download the moment payment clears
• Indexed PDF search covers every chapter and appendix
• how factory workshop documentation is structured
• This original OEM publication provides the exact torque values and setup parameters required for the 1986 race season build

Component and System Documentation

The 1986 Yamaha YZ125S service manual documents technical systems spanning general maintenance to full engine overhauls. Chapter topics include comprehensive machine identification, fluid and coolant specifications, engine maintenance and repair, chassis component servicing, and appendixed tuning data. Each section integrates clear exploded diagrams to assist in component identification and assembly visualization.

Specification Highlights

The cylinder head warpage limit is documented at 0.03 mm in the engine specification table. Piston clearance for the 1986 Yamaha YZ125S engine is specified at 0.055–0.060 mm. The drive sprocket securing nut torque is 60 Nm, as provided in the chassis assembly data. The manual provides precise torque settings for critical assemblies, including steering stem nuts, cylinder holding nuts, and brake disc fasteners, ensuring alignment with factory standards. All service data shown here is for reference only — qualified technicians and the original OEM documentation remain the authoritative source for any hands-on work. This official 100-page Yamaha OEM publication covers the 1986 YZ125S, documenting engine, chassis, and suspension specifications for the complete competitive maintenance of this model.