1979-1985 Suzuki GS/GSX 250, 400 & 450 Twins Repair Manual
Complete service and maintenance procedures for GS250T, GSX250E, GSX400E/T, and GS450 models. Covers engine, clutch, gearbox, fuel system, ignition, and chassis repairs with detailed specifications and torque settings.
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Sample pages from the 1979-1985 Suzuki GS/GSX 250, 400 & 450 Twins Repair Manual manual
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Suzuki Models Covered & Key Technical Specifications
Models: Suzuki GS250, Suzuki GSX250, Suzuki GS400, Suzuki GS450
Sub-models / Variants: GS250T, GS250E, GSX400T, GSX400E, GS450E, GS450L, GS450S, GS450T, GS450TX, GSX250/400 EZ
Trade Names: GS Series, GSX Series
Build Years: 1979–1985
Serial Numbers: Located on frame (steering head) and upper crankcase
Technical Data:
- Engine: Twin cylinder, air-cooled, DOHC, 4-stroke
- Displacement: 249 cc (250 models), 399 cc (400 models), 448 cc (450 models)
- Compression Ratio: 10.5:1 (250 models), 10.0:1 (400/450 models)
- Valve Clearance (Cold): 0.08–0.13 mm (0.003–0.005 in)
- Ignition Timing: 1650 ± 100 rpm (250 models), 1100 ± 50 rpm (400 models)
- Spark Plug Gap: 0.6–0.7 mm (0.024–0.028 in)
- Gearbox: 6-speed constant mesh
- Fuel Capacity: 11–14.5 liters (2.4–3.8 Imp/US gallons)
- Engine Oil Capacity: 2.0 liters (change only), 2.6 liters (with filter), 3.0 liters (overhaul)
- Fuel Type: Gasoline (petrol)
- Drive System: Chain drive
Suzuki Manual Features & Content Preview
Suzuki GS/GSX 250, 400 & 450 Twins: Owner Workshop Manual
- Covers 1979–1985 Suzuki GS and GSX twin-cylinder models from 249 cc through 448 cc, including E, L, S, T, and TX trim variants
- Third-party publication by Haynes Publishing Group, ISBN 1 85010 253 8, copyright 1990 edition
- Contains 124 exploded-view diagrams, 75 photographic maintenance sequences, and detailed torque-setting reference tables
- Downloads to your account within seconds of checkout
- Unlimited re-downloads tied to the purchase record
- Full-text search finds any part number in seconds
- Laid out for standard letter and A4 printing
- This 1990 manual provides the historical record and specific adjustments required for the air-cooled Suzuki GS and GSX twin-cylinder engine architecture.
What the Manual Documents:
The Suzuki GS/GSX 250, 400 & 450 Twins repair manual serves as a definitive resource for owners performing routine maintenance and major mechanical work. The document structure begins with fundamental workshop setup, tools, and safety, before delving into extensive chapters on the engine, clutch, and gearbox. Further sections detail the fuel system, lubrication, ignition, frame, forks, wheels, brakes, and electrical systems. The final chapters provide wiring schematics, terminology translation, and conversion tables, ensuring what an OEM service publication covers is fully articulated for the home mechanic.
Technical Depth and Specifications:
This Suzuki GS/GSX 250, 400 & 450 twins publication documents engine assembly clearances, including vital crankshaft and balancer shaft bearing selection tables. Cylinder head bolt torque is specified at 16–20 lbf ft (2.2–2.8 kgf m) in the engine specification data. The manual documents valve clearance for the intake and exhaust at 0.08–0.13 mm. Coolant-less, the Suzuki GS/GSX 250, 400 & 450 twins engine oil capacity is defined at 2.6 liters with filter. Gearbox components, including selector forks and pinion teeth wear limits, are explicitly cataloged in the service data tables. An official 200-page Haynes workshop manual covering the 1979–1985 Suzuki GS and GSX 250, 400, and 450 twins, documenting engine, chassis, electrical, and fuel-injection specifications for the respective air-cooled twin models.
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