1991 Suzuki DR650S (DR650SM) Factory Service & Repair Manual (P/N 99500-46020-03E)

This Suzuki DR650S factory service manual covers maintenance, diagnosis, and repair in nine chapters, including the dedicated DR650SM ('91-model) update. The update adds model-specific service data and routing information to the main workshop procedures.

• Maintenance and engine repair: Periodic maintenance chart, valve-clearance and decompression adjustment, engine removal, cylinder-head service, crankcase disassembly, and reassembly.

• Clutch and transmission: Clutch inspection, kick-starter service, countershaft and driveshaft assembly, gearshift-fork checks, and transmission installation details.

• Fuel and lubrication: MIKUNI BST40SS disassembly, needle-valve inspection, float-height adjustment, oil-pressure testing, and oil-cooler documentation.

• Electrical diagnosis: Ignition-coil and magneto tests, CDI and regulator/rectifier checking tables, charging-system checks, and switch-continuity diagrams.

• Brakes and wheels: Front and rear caliper and master-cylinder service, brake bleeding, disc inspection, wheel-bearing replacement, and wheel-runout checks.

• Suspension and steering: Front-fork disassembly and reassembly, steering-bearing adjustment, swingarm inspection, and rear suspension-linkage bearing service.

The foreword identifies experienced mechanics as the primary readers and also addresses apprentice and do-it-yourself mechanics; internal repairs call for the specified measuring equipment and special tools.

Engine, Balancer, and Transmission Service

Internal engine coverage extends to valve-guide replacement and seat reconditioning, piston and cylinder inspection, and camshaft journal checks using Plastigauge. Exploded clutch drawings and a transmission cross-sectional view show the relationships between plates, gears, washers, and circlips. A valve timing diagram accompanies the camshaft inspection material.

Balancer service distinguishes the manually adjusted balancer-chain tensioner from the automatic cam-chain tensioner. The primary drive gear nut is specifically identified as having a left-hand thread.

The crankcase-separation caution explains how incorrect placement of the transmission components can damage the gearshift cam stopper. Shift fork-to-groove clearance tables and assembly illustrations support inspection of the closely related shifting components.

Carburetor Variants, Oil Cooling, and Emissions

MIKUNI BST40SS specification charts match carburetor identification numbers to regional jetting. The DR650SM chapter revises selected needle and pilot-circuit entries, including U.S. and California specifications. These distinctions help identify the appropriate carburetor configuration before replacement components are selected.

The emission-control section distinguishes close-tolerance jets from standard jets and describes the factory-sealed pilot circuit. California coverage includes the evaporative-emission system schematic and canister hose routing. The Switzerland-only secondary-air section provides hose-routing and mounting details.

The engine lubrication/cylinder-head cooling system chart traces the oil cooler, oil jets, and bearing feeds. Oil-pressure testing includes possible causes of abnormal readings and identifies oil pressure gauge 09915-74510.

Electrical Fault Finding and Chassis Repair

The PEI ignition and charging sections provide resistance values for the pick-up and power source coils, along with ignition-coil tests and CDI checking tables. The manual identifies Suzuki pocket tester 09900-25002 and explains that readings for electronic units can differ with other ohmmeters, an important distinction when assessing a suspected component fault.

Separate wiring diagrams cover U.S./Canada and other-market configurations. Wire, cable, and hose-routing illustrations support reinstallation, while troubleshooting tables connect starting, running, charging, and chassis symptoms with possible causes and remedies.

Chassis procedures include steering-race replacement and fork oil-level setting. Fork assembly cautions identify the Teflon-coated bushings as vulnerable to installation damage. Rear-suspension coverage addresses shock removal and inspection, plus swingarm and cushion-linkage bearing service.

Review the factory safety precautions before working on the fuel, ignition, or brake systems, including the specified brake-fluid handling and bleeding precautions.

A Preview of Valve Settings, Head-Bolt Torque, and Oil Capacities

Intake and exhaust valve clearance is specified at 0.08–0.13 mm with the engine cold. The cylinder-head assembly instructions specify 35–40 N·m for the head bolts, with separate specifications for the head nuts.

The oil-capacity tables distinguish 2,000 ml for an oil change, 2,150 ml with a filter change, and 2,600 ml after engine overhaul. These entries distinguish routine service fills from the amount required following internal engine work.

PDF Reading, Wiring Detail, and Page Contents

Text search and diagram viewing: PDF text search and embedded bookmarks are not available. The full wiring diagrams are oriented sideways; rotating the view and zooming makes their small wire-color codes and switch labels readable.

Supplied as one printable English PDF with 188 pages, including the front cover and two blank pages. The 12-page DR650SM update chapter occupies PDF pp. 176–187 within the same file.