1981–1982 Suzuki GS650 Katana Service & Repair Manual (P/N 99500-36000-01E)

• Model coverage: Matches the shaft-drive Suzuki GS650GX ('81) and GS650GZ ('82) Katana, using the core GS650GT workshop sections together with the year-specific GX and GZ material.
• Engine and transmission repair: Covers engine removal and installation, full disassembly and reassembly, cylinder-head and valve service, cam timing, pistons and crankshaft, clutch and starter clutch, oil pump, and constant-mesh transmission inspection.
• Shaft-drive setup: Details the output shaft, secondary bevel gear, propeller shaft, and final drive, with factory procedures for shim selection, bearing preload, backlash, and tooth-contact checks.
• Fuel and tune-up work: Provides Mikuni BS32SS carburetor disassembly, inspection, reassembly, float and fuel-level adjustment, carburetor balancing, valve-shim selection, compression testing, oil-pressure testing, and ignition-timing checks.
• Chassis and brake service: Includes front and rear wheel bearings, steering stem, swingarm, adjustable forks and rear shocks, disc-brake calipers and master cylinders, brake-pad replacement, and hydraulic bleeding.
• Electrical and 1982 systems: Covers charging, ignition, starter, meter, lamp, and switch tests, plus GZ fuel-gauge diagnostics, anti-dive fork inspection and bleeding, routing layouts, and market-specific wiring diagrams.

This 356-page English-language PDF covers the 1981 GS650GX and 1982 GS650GZ versions of Suzuki's shaft-drive GS650G Katana, powered by the 673 cc air-cooled DOHC four-cylinder engine. It combines the main GS650GT service material with GX and GZ supplementary sections that identify model-year differences. For 1982 repair, the GZ section takes precedence; earlier chapters apply where procedures are unchanged. Suzuki describes the material as aimed primarily at experienced mechanics while also useful to apprentices and do-it-yourself mechanics; precision engine and final-drive overhaul still assumes suitable measuring equipment and workshop experience.

Engine, Fuel, and Final-Drive Overhaul

The engine chapter distinguishes parts that can be serviced in the frame from work requiring complete engine removal. Its overhaul coverage runs through valve-guide replacement and reaming, valve-seat service, camshaft and cam-chain inspection, piston and ring fitting, connecting-rod and crankshaft bearing selection, clutch and starter-clutch repair, transmission shaft diagnosis, and final engine assembly. Carburetor material explains the slow, main, and starter circuits before moving into rack disassembly, jet and needle-valve inspection, float setup, reassembly, and synchronization.

The shaft-drive chapter goes well beyond basic gear-oil maintenance. It covers output cam-dog service, secondary driven bevel-gear overhaul, final gear-case removal and disassembly, seal and bearing replacement, and the linked adjustments for preload, backlash, and tooth contact. Suzuki warns that the final-drive coupling nut sets bearing preload by crushing a one-use spacer; if preload is exceeded, backing off the nut is not an acceptable correction because the spacer must be replaced.

1982 GZ Changes and Production Breaks

The GZ section documents the handlebar-mounted choke control, revised front brake reservoir, coil-type fuel gauge and sending-unit tests, side-stand warning circuit differences by market, replacement-only oil pump, adjustable rear-shock damping, and the hydraulic anti-dive front fork. Anti-dive coverage explains the separate brake-fluid and fork-oil circuits, modulator inspection, fork removal and reassembly differences, and the required bleeding sequence.

Parts selection is tied to actual production changes. The manual identifies revised connecting-rod and crankshaft-journal bearings from GS650G/GL/GT engine No. 122709, a late fork cap and spring adjuster from GS650G Katana frame No. 129208, and the added primary-driven-gear spacer shim from GS650G engine No. 147477. The crankshaft update also carries a critical repair warning: putting a non-grooved journal bearing in the lower crankcase disrupts oil distribution and can damage internal engine parts.

Test Data, Tools, and Diagrams

Complaint/cause/remedy charts cover engine, carburetor, charging, ignition, starting, steering, suspension, and brake faults. Factory tables collect component torques, fluid specifications and capacities, electrical test values, clearances, wear limits, and shim-selection data. Listed Suzuki tools include the carburetor balancer gauge set 09913-13121, tappet depressor 09916-64510, clutch sleeve-hub holder 09920-53710, final-drive coupling holder 09924-64510, and steering-nut socket 09940-14911.

Exploded assemblies and service illustrations include the final gear-case breather circuit, secondary and final bevel-gear tooth-contact patterns, the coil-type fuel-gauge circuit, anti-dive fork sectional views, wire-and-cable routing layouts, and destination-specific wiring diagrams. The file consists of one cover page, 239 pages of core material, a 68-page 1981 GX section, a 46-page 1982 GZ section, and two full-page color wiring diagrams. The core scan begins at General Information page 1-10; pages 1-1 through 1-9 are absent. The second color diagram also identifies the shared 1982 GS650GZ/1983 GS650GD circuit, but the PDF does not provide full 1983 repair coverage. It omits the GS650GLX and GS650GTZ/GLZ supplementary sections found in the broader multi-variant binder.

Engine removal, spring-loaded driveline parts, final-drive setup, and hydraulic brake or anti-dive repair require secure support, the specified measuring tools, and proper shop safety practices.