1976–1980 Suzuki GS550 / GS550E / GS550L Service Manual (P/N 99500-35003-01E)

• 716-page PDF of Suzuki’s GS550 Service Manual, Manual No. 99500-35003-01E, for the air-cooled DOHC four-cylinder models listed below.
• Engine removal and crankcase disassembly, with cylinder-head repair, cam-chain timing, and tensioner service.
• Transmission gear inspection, wet multiplate clutch overhaul, and shift-fork and shift-drum checks.
• Carburetor balancing and overhaul for Mikuni VM22SS and BS32SS systems, including float-level inspection.
• Steering stem maintenance, front fork suspension rebuilds, rear shock absorber inspection, and swingarm bearing replacement.
• Hydraulic brake repair covering caliper and master-cylinder overhaul and bleeding, plus rear drum brake service.
• Electrical diagnosis for contact-breaker and transistorized ignition, charging-system tests, and starter motor repair.

This manual was written primarily for workshop mechanics and is also intended as a guide for owners experienced in servicing Suzuki motorcycles. This is the seventh edition, dated October 1990; the first edition was published in January 1977.

GS550 and GS500 Model Coverage

The main manual and its supplements cover the following model groups. Supplements document changes and refer back to earlier sections for procedures that remain applicable.

The GS500 coverage concerns the four-cylinder models in the 1981 supplement. Market sections distinguish general specifications (E-01), U.S. specifications (E-03), and Canadian specifications (E-28), with additional country-specific data where equipment differs.

Engine Repair and Model-Specific Changes

Engine coverage extends to valve-guide replacement and reaming, valve-seat refinishing, camshaft journal-clearance inspection, and piston and cylinder wear assessment. Valve-clearance adjustment is supported by a tappet-shim chart listing sizes and part numbers. The engine chapter also identifies assemblies that can be serviced with the engine installed.

A camshaft, sprocket, and bolt revision chart explains the limits of parts interchangeability: the later 7 mm fastener arrangement does not interchange with the earlier 6 mm versions. This distinction matters when matching replacement camshafts and sprockets.

The carburetor sections distinguish the mechanically operated VM22SS from the vacuum-piston BS32SS. U.S. emission-control sections explain the use of close-tolerance jets and factory-set mixture adjustments, including sealed idle circuits on the BS32SS.

Chassis differences include spoked and cast wheels, single- and twin-disc front brakes, and rear disc or drum brakes. The GS550D’s spoked-wheel, twin-front-disc configuration is identified separately. U.S. and Canadian GS550LZ coverage includes air-assisted forks. The fork reassembly cautions address damage to the Teflon-coated bushings during installation; drive-chain service notes identify solvent damage to the chain’s O-rings.

Engine and Chassis Data Preview

The documentation includes compression and oil pump pressure tests, cylinder-head nut tightening specifications, intake and exhaust valve-clearance data, and engine and transmission wear limits. Component-specific torque tables, fluid capacities, lubrication requirements, and electrical test values accompany the relevant service sections.

Technical illustrations include valve-timing diagrams, transmission assembly views, BS32SS fuel-circuit section views, and exploded views of the GS550E wheels. Fuel-gauge troubleshooting charts support fault isolation between the gauge and sending unit. Market-specific wiring diagrams are supplemented by wire, cable, and brake-hose routing drawings.

Charging-system coverage distinguishes separate regulator and rectifier components from the integrated regulator/rectifier unit. Coil, pickup, and ignitor tests address the transistorized ignition variants. The special-tool listings identify the tappet depressor 09916-64510 and carburetor balancer set 09913-13121, making the required workshop equipment clear before a repair is planned.

Work on these vintage engines, steering assemblies, and brakes requires adherence to the applicable factory tolerances and safety precautions.

Note: This page serves as a content overview and specification preview for the manual. It does not contain the actual step-by-step repair or diagnostic instructions.