Suzuki Bandit GSF400 1989–1991 Service & Parts Manual Set

Use the service manual for inspection and repair procedures. The parts catalog uses exploded drawings, frame-number starts, and application notes to help identify the correct OEM parts before ordering.

Service coverage ends with Section 9, Emission Control Information. The M/N/P model-specific applications are in the parts catalog. For California Model P, the catalog flags the affected carburetor component numbers as pending a revised edition.

PDF Files and Diagram Readability

Text search and navigation: All files lack built-in text search and PDF bookmarks. Use the printed page numbers to navigate Section 7, where pages are stored out of order. The full wiring diagrams in Section 8 benefit from zooming, and some small connector and wire labels remain hard to distinguish.

The ZIP contains 10 printable PDFs in English, with one file per service chapter and one for the parts catalog. The 309-page total includes nine chapter contents pages and two introductory catalog pages.

Engine Overhaul, Chassis Service, and Parts Identification

This selection of topics covers workshop procedures and parts lookup. The service manual also covers body panel removal and battery recharging.

• Maintenance and engine: Factory maintenance chart, lubrication points, compression and oil pressure checks, engine removal and installation, complete teardown and reassembly, clutch service, and transmission and gearshift repair.
• Fuel and lubrication: Fuel tank and fuel cock service, four-carburetor rack removal, inspection, float adjustment and synchronization, plus oil pump inspection and the engine lubrication chart.
• Cooling and emissions: Cooling system and radiator cap pressure tests, thermostat and thermoswitch checks, fan diagnosis, water pump service, and California canister and hose routing.
• Chassis: Front and rear wheel service, tire removal and mounting, brake calipers and master cylinders, fork overhaul, steering stem, swingarm, cushion lever, and rear shock preload.
• Electrical diagnosis: Charging and digital ignition tests, starter motor and relay service, side-stand interlock checks, and troubleshooting for the combination meter, lighting, switches, and battery.
• OEM parts identification: 54 numbered exploded-parts figure groups plus five A-suffix figures, including separate Model P headlamp and brake hydraulic illustrations.
• Service data: Symptom, cause, and remedy charts, cable and hose routing, special-tool numbers, torque tables, clearances, wear limits, fluid capacities, and tire pressures.

The service manual is suited to technicians and experienced home mechanics who can interpret wear limits and use the specified measuring tools.

Engine and Carburetor Work

The overhaul procedures cover valve guide removal and reaming, valve seat cutting, camshaft runout and journal clearance, piston and ring inspection, and crankshaft and connecting rod bearing selection using Plastigauge. The transmission section covers gear and shift fork inspection. An in-frame service list identifies which components can be removed with the engine still installed.

Uneven tightening of the camshaft journal holders can damage the cylinder head or holder thrust surfaces.

The carburetor section explains the slow, main, starter, and float circuits and covers rack disassembly and reassembly. The emissions section identifies the close-tolerance main, needle, and pilot jets and explains the factory-sealed pilot screw. It also shows fuel, vacuum, and air vent hose routing for the California evaporative system.

Parts Fitment, Wiring, and Chassis Tools

The parts catalog separates M/N and P applications and flags California-only carburetor, igniter, wiring harness, fuel tank, and emissions parts. Its engine-number breaks distinguish cylinder-head hose and lower crankshaft bearing applications.

The electrical chapter shows how to trace the side-stand and neutral switches through the ignition interlock. Section 8 provides separate full wiring diagrams for the U.S. and Canada, West Germany, and other markets.

Fork procedures cover the damper rod, bushings, seals, and oil level. The factory tool references include carburetor balancer 09913-13121, digital ignitor checker 09931-94430 with adapter 09931-94460, fork oil seal installer 09940-50113, steering stem nut wrench 09940-14911, and fork oil level gauge 09943-74111.

The brake procedures specify fresh brake fluid for cleaning hydraulic components. Spilled fluid can damage paint, plastic, and rubber, and high-pressure air can damage caliper pistons. Brake hydraulics, steering, suspension, and internal engine repairs should be handled by a qualified technician when the specified tools, secure support, or inspection experience are unavailable.

Charging and Thermostat Test Examples

The GSF400 charging check specifies 13.5–15.5 V DC at the battery at 5,000 rpm with a fully charged battery and the high beam on. The separate cold-engine generator test calls for more than 70 V AC between generator leads at 5,000 rpm with the generator disconnected from the harness.

For the cooling system bench test, the thermostat should begin opening at 74.5–78.5 °C.