Yamaha YZ450F & YZ450FX Competition Motocross Owner's Service Manual (2008)

Yamaha YZ450F & YZ450FX Competition Motocross Owner's Service Manual (2008)

Take full command of your high-performance racing machine with the definitive 2008 Yamaha YZ450F and YZ450FX Owner's Service Manual. This professional-grade technical reference is the same guide used by factory-trained mechanics to maintain the precision engineering of Yamaha’s championship-winning motocross series. Specifically covering the 2008 model year (1st Edition, May 2007), this manual provides the exhaustive data required to keep your 449cc liquid-cooled engine and sophisticated chassis in peak race-ready condition.

Engineered for Elite Competition

The 2008 YZ450 series represents the pinnacle of Yamaha's racing craftsmanship, designed strictly for competition use on closed courses. This manual is tailored for experienced riders and technicians who demand absolute reliability and maximum power. Whether you are performing a routine oil change or a complete engine overhaul, the sequential, step-by-step formats and detailed exploded diagrams ensure every procedure is completed with surgical accuracy.

Deep Technical Specifications & Performance Tuning

• Precision Engine Management: Access critical data for the 449cc 5-valve DOHC engine, including exact valve clearances (Cold: IN 0.10–0.15mm / EX 0.20–0.25mm) and cylinder head warpage limits (0.05mm).
• Professional Carburetor Calibration: Master the Keihin FCR-MX39 carburetor with full jetting specifications, including the standard #160 main jet, #45 pilot jet, and NFLR-3 jet needle clip position.
• Advanced Suspension Settings: Optimize your KYB telescopic forks and Monocross rear suspension with detailed click-adjustment settings for rebound and compression damping, as well as spring rate data.
• Race-Ready Torque Specs: Ensure structural integrity with comprehensive torque values for every fastener—from the cylinder head bolts (initial 30 Nm followed by 180° angle) to the 105 Nm front wheel axle nut.

Critical Identification & Serial Numbers

To ensure you are ordering the correct genuine Yamaha parts and to protect your investment, this manual provides precise locations for all vital serial numbers:

• Vehicle Identification Number (VIN): Stamped on the right side of the steering head pipe.
• Engine Serial Number: Stamped into the elevated part of the right side of the engine.
• Model Label: Located on the frame under the rider's seat.
• Model Codes: Covers 2S2B (USA, Canada), 2S2C (Europe), and 2S2E (AUS, NZ, South Africa).

Comprehensive Content Overview

• General Information: Pre-operation checklists, break-in procedures, and control functions.
• Specifications: Detailed engine, chassis, and electrical maintenance specifications.
• Regular Inspection & Adjustments: Vital maintenance intervals for the cooling system, drive chain, and brakes.
• Engine Overhaul: Complete teardown and assembly for the cylinder head, camshafts, oil pump, and transmission.
• Chassis & Suspension: Full service guides for front fork maintenance and rear shock absorber tuning.
• Electrical System: CDI magneto data, ignition timing checks, and full wiring/cable routing diagrams.
• Tuning: Professional adjustments for the carburetor and chassis to match varying track conditions.

This manual is an essential asset for any serious Yamaha owner, ensuring your machine continues to deliver the highest grade of performance and reliability that makes Yamaha a leader on the track.