Suzuki DR650S DR650SM Motorcycle - Comprehensive Service Manual 1991

Suzuki DR650S & DR650SM (1991) - Comprehensive Service Manual

The Suzuki DR650S Service Manual is the definitive professional-grade resource for maintaining and repairing one of the most versatile dual-sport motorcycles ever built. This comprehensive guide is specifically engineered for the 1991 model year, covering both the standard DR650S and the specialized DR650SM variants. Whether you are a professional technician or a dedicated DIY enthusiast, this manual provides the deep technical insight required to keep your 640cc four-stroke thumper running at peak performance.

Beyond the Basics: Model Focus and Technical Insight

The 1991 Suzuki DR650 series was designed to dominate both pavement and trails through a sophisticated blend of lightweight engineering and reliable four-stroke power. This manual delves into the specific systems that define the DR650 experience:

• Advanced Engine Design: Detailed service procedures for the 640cc SOHC, air-cooled engine, featuring specialized sections on the engine counter-balancers and the unique cylinder head cooling system.
• Precision Chassis Engineering: Comprehensive data for the "Full Floating" rear suspension system and telescopic pneumatic/coil spring front forks.
• Transmission Mastery: Step-by-step disassembly and reassembly of the 5-speed constant mesh transmission, including specific instructions for the primary kick starter system.

Crucial Identification Data

To ensure you are ordering the correct spare parts and performing the right service, this manual provides exact locations for vital machine numbers:

• Frame Serial Number (V.I.N.): Stamped directly on the steering head pipe.
• Engine Serial Number: Stamped on the engine crankcase.

Comprehensive Contents for Every Service Task

This manual is organized into clear, logical sections to make navigation effortless:

• General Information: Full technical specifications, dry mass data (335 lbs), and fuel/oil recommendations (SAE 10W/40).
• Periodic Maintenance: A complete maintenance chart and schedule, including critical valve clearance adjustments (0.08–0.13 mm for both IN and EX).
• Engine Overhaul: Complete guides for cylinder head servicing, piston ring replacement, and crankshaft installation using specialized tools.
• Fuel and Lubrication: Detailed specifications for the MIKUNI BST40SS carburetor, including float height adjustments (14.7mm) and idle speed settings (1,300–1,500 r/min).
• Electrical System: Full wiring diagrams, ignition timing data, and CDI unit testing procedures.
• Emission Control: Essential information to keep your DR650S compliant with EPA regulations.

Why This Manual is Essential

• Detailed Specs: From the 95.0mm bore and 90.4mm stroke to the exact tightening torques for every chassis bolt, no detail is omitted.
• Professional Guidance: Written primarily for experienced mechanics, providing the level of detail missing from basic owners' manuals.
• Reliability First: Includes specialized "Break-In" procedures and "Special Materials" sections (like Suzuki Moly Paste and Thread Lock requirements) to maximize your motorcycle's longevity.

Protect your investment and master your machine with the most up-to-date repair techniques and specifications available for the 1991 Suzuki DR650 series.