Yamaha YZ125(P)/LC 2-Stroke Service Manual • P/N 5NY-28199-30.

Yamaha YZ125(P) and YZ125LC Technical Overview

• Covers 2001 Yamaha YZ125(P) and YZ125LC 2-stroke motocross machines across USA, CDN, AUS, NZ, ZA, and EUROPE markets
• Official Yamaha factory publication (P/N 5NY-28199-30)
• Contains 47 torque-check specification tables, 3 electrical schematic guides, and 5 detailed exploded-view procedures
• Fully searchable: The OCR text layer lets you jump straight to a torque spec or part by keyword
• Available as an instant download immediately after checkout

When tuning the 2001 YZ125 competition model, having accurate foundational data is critical. This 561-page document serves as the primary reference for the global 5NY-series build. It outlines fundamental machine identification, pre-operation checks, and detailed system specifications. You get a clear breakdown of engine overhaul parameters, carburetor settings, and chassis adjustments. Transmission, cylinder head, piston, and ignition components are mapped out with exact factory tolerances and service limits.

Working on high-performance 2-strokes requires strict adherence to factory limits to ensure safe and reliable operation; always verify hardware conditions before applying these specifications. The technical sections dive deep into the numbers. For instance, you will find comprehensive torque values for engine covers, cylinder head studs, and suspension linkages. It documents the cooling system capacity at 0.95 liters across all variants. Need precise measurements? The intake reed valve thickness is specified at 0.42 mm, and the ignition coil secondary winding resistance is listed at 6.7–10.1k ohms at 20°C.