Yamaha YZ125B motorcycle owner's service manual: 1991 repair guide
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Sample pages from the Yamaha YZ125B motorcycle owner's service manual: 1991 repair guide manual
Purchase Information
Technical Specifications
- Document Number / Seller:
- 26554 / Christopher Garcia
- File Size:
- 35.99 MB
- File Type:
- ZIP
- Language:
- English
- Pages:
- 175
- Printable:
- Yes
- Estimated Download Time:
- 0.74 Minutes
- Delivery Format:
- Digital (PDF) - Instant Access
- Category:
- Bike
- Brand:
- Yamaha
- Reviewed and Approved:
- Dec 30, 2025
Yamaha Models and Parts Covered in this Bike Manual
YZ125B / Yamaha Motor Co., Ltd
- Yamaha YZ125B (1991)
- Yamaha YZ 125 (1991)
- Yamaha YZ125/LC (1991)
- Yamaha YZ125B/LC (1991)
Complete Manual Information
Yamaha YZ125B 1991 Motorcycle Owner's Service Manual – The Ultimate Professional Repair Guide
Master Your Machine with the Original 1991 YZ125 Competition Specialist Manual
Don't settle for generic repair books. This is the authentic, high-detail Owner’s Service Manual specifically engineered for the legendary 1991 Yamaha YZ125B series. Whether you are a professional mechanic or a dedicated privateer racer, this 175-page technical guide provides the precision data required to maintain peak performance and factory reliability for your 124cc liquid-cooled racing machine.
This manual is not just a collection of instructions; it is a comprehensive technical blueprint designed for the 3XJ model generation. It covers everything from basic pre-race inspections to complete engine blueprints and advanced suspension tuning.
Extensive Model Coverage & Identification This manual is specifically written for the 1991 model year (3XJ series) and includes data for international variants. For precise identification, refer to the following starting serial numbers included in this documentation:
- Yamaha YZ125B (1991) - USA/Canada: JYA3XJW0MA008101
- Yamaha YZ125B (1991) - Australia: JYA3XJT0MA020101
- Yamaha YZ125 (1991) - Europe: 3XJ-000101
- Yamaha YZ125/LC (1991) - Africa/ZA: 3XJ-008101
Why This Manual is Essential for Your Garage:
- Full Engine Blueprinting: Detailed procedures for the liquid-cooled 2-stroke engine, including precise Y.P.V.S. (Yamaha Power Valve System) governor adjustments and cylinder head warp limits (0.03 mm).
- Pro-Level Suspension Tuning: Specialized sections for the telescopic front forks and the New Monocross rear suspension. Includes exact oil capacities (564 cm³ for US models) and clicker setting guides for rebound and compression damping.
- Precision Specifications: Get the exact torque values for every bolt, from the M14 spark plug (18 ft-lb) to the critical M18 rear axle nut (85 ft-lb).
- Fuel System Mastery: Complete breakdown of the Mikuni TM35SS carburetor, including float arm height settings (15.2–17.2 mm) and specific jetting charts for various climates and altitudes.
- Electrical Clarity: Full wiring diagrams and CDI magneto inspection steps, including resistance values for the charging and pickup coils.
Clear Benefits for the Rider and Mechanic:
- Eliminate Guesswork: Use the exact factory-specified tolerances (like the 0.5–0.6 mm spark plug gap) to ensure your bike runs like it just rolled off the showroom floor.
- Save Time & Money: Step-by-step illustrated assembly guides and "Removal Points" help you avoid common mistakes during complex tasks like a crankcase split or transmission overhaul.
- Peak Performance: The dedicated "Tuning" chapter gives you the edge on the track with gearing ratio charts and spark plug heat range analysis.
Technical Highlights Included:
- Complete Maintenance Schedules (Break-in to Every Race)
- Engine Overhaul (Piston, Crankshaft, Clutch & Transmission)
- Cooling System Service (Radiator & Water Pump)
- Chassis & Wheel Maintenance (Spoke Tightening & Brake Bleeding)
- Specialized Tool Lists (Yamaha Part Numbers YU/YM/YS)
Stop struggling with blurry internet forum advice. Invest in the technical authority for your 1991 Yamaha YZ125B and keep your machine at the front of the pack. This manual is formatted for easy reading on mobile devices in the pits or at the workbench.
Product Specifications:
- Compatible with: 1991 Yamaha YZ125 (B-Series)
- Document Type: Combined Owner's & Service Manual
- Page Count: 175 Pages
- Language: English (US)
- System Coverage: Engine, Chassis, Electrical, Cooling, Fuel, Tuning
Download Instructions for Yamaha Bike Manual
Frequently Asked Questions - Yamaha Bike Manual
Is this manual suitable for beginners?
Yes, this Yamaha manual is designed for both professional technicians and DIY enthusiasts. It includes step-by-step procedures with clear illustrations and safety guidelines for Bike maintenance and repair.
What file format will I receive?
You will receive this manual as a ZIP file (35.99 MB), which is compatible with all devices. The manual is fully searchable and printable for your convenience.
How quickly can I access the manual after purchase?
You'll receive instant access to your Yamaha Bike manual immediately after payment completion. The download link is valid for 3 days, with lifetime re-download guarantee.
Can I print specific sections of the manual?
Absolutely! This digital manual allows you to print any section you need, from individual pages to complete chapters, making it perfect for workshop use.
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