1999 Yamaha YZ250(L)/LC Factory Service Manual (P/N 5CU-28199-30)

• Covers 1999 Yamaha YZ250(L)/LC competition motocross machines, including YZ250LC (Europe), YZ250L1 (USA), and YZ250(L) (CDN, AUS, NZ, ZA) variants.
• Official Yamaha publication P/N 5CU-28199-30 detailing the exact factory launch specifications.
• Contains illustrated exploded-view diagrams, torque tables, and cable routing schematics for swift shop reference.
• This comprehensive first edition is the definitive technical reference for the 5CU model series build and the 249 cm³ liquid-cooled powerplant.

Manual Contents Overview

The 1999 Yamaha YZ250(L)/LC service manual documents essential diagnostic procedures and component service routines. This publication provides the necessary data for internal engine overhauls, transmission maintenance, and chassis setups. It includes detailed exploded diagrams mapping out the cooling, fuel, and electrical systems. For professional technicians and dedicated DIY enthusiasts, having accurate factory specifications on hand eliminates guesswork and maximizes shop efficiency. It clearly outlines the preparation steps and routine maintenance cycles essential to keeping this 2-stroke racing machine competitive.

Engine and Chassis Specification Highlights

Working on high-performance competition motorcycles requires strict adherence to factory tolerances to maintain structural integrity and rider safety. This document contains extensive technical specifications outlining the mandatory torque values for engine mounts, steering hardware, and brake components to ensure safe operation. The technical data details a crucial piston-to-cylinder clearance of 0.045–0.050 mm and a primary reduction ratio of 3.000 for the constant-mesh transmission.

You will also find comprehensive baseline jetting data for the 5CU-series Keihin PWM38 carburetor. The coolant system capacity is officially documented at 1.20 liters, and the required spark plug gap is specified at 0.5–0.6 mm. Furthermore, the chassis section covers essential suspension data, detailing the exact rear shock absorber rebound damping and compression force adjustments. This OEM document acts as a descriptive reference for professional shop repair procedures, offering deep mechanical insights without serving as a basic step-by-step beginner guide.