1972–1978 Suzuki GT 380 Service & Repair Manual

This factory service manual for the 1972–1978 Suzuki GT 380 was issued by Suzuki Motor Co., Ltd.’s Export Service Section. It covers the RAM AIR model with VM24SC carburetors and front and rear drum brakes.

• Engine repair: Engine removal, cylinder-head inspection, piston and ring checks, crankcase separation and assembly, and crankshaft installation precautions.

• Clutch and transmission: Wet multi-disc clutch disassembly, wear inspection and adjustment, transmission installation, gear-position diagrams, and kick-starter assembly details.

• CCI lubrication and SRIS: Oil-pump delivery testing, control-cable adjustment, bleeding procedures, and Suzuki Recycle Injection System hose routing.

• Carburetor service: VM24SC overhaul, idle adjustment, throttle synchronization, float-level setting, and checks for fuel overflow.

• Electrical diagnosis: DENSO and KOKUSAN charging-system tests, contact-breaker timing, ignition-coil and condenser specifications, and wiring diagrams.

• Chassis maintenance: Front-fork overhaul, drum-brake inspection and adjustment, drive-chain service, rear-wheel removal, and steering-stem checks.

Written for trained service personnel, this manual assumes existing workshop skills and familiarity with the measuring equipment and special tools used in its procedures.

Engine, Clutch and Transmission Repair

The engine chapters cover cylinder-head distortion checks, cylinder wear measurement, piston-ring orientation, and piston inspection. Crankshaft installation notes address bearing locating pins and oil-seal positioning; the oil-seal and bearing sections explain installation and inspection methods.

Clutch coverage extends to drive-plate wear, spring condition, sleeve-hub damage, and release-system adjustment. The exploded view of transmission identifies gear and washer positions, while separate illustrations show neutral and each gear engagement. The kick-starter section explains the primary starting mechanism and its assembly alignment.

The troubleshooting tables connect hard starting, overheating, abnormal engine noise, clutch faults, and shifting problems with likely causes. Engine performance curves and the exploded view of engine provide supporting reference material.

VM24SC Carburetors, CCI Oil Delivery and SRIS

Carburetor coverage distinguishes idle balancing from throttle-valve synchronization and explains how cable adjustment affects the oil-pump setting. Float and needle-valve inspections address overflow, and mounting marks distinguish the left, center, and right carburetors.

The Suzuki CCI section includes oil-pump performance curves and measured delivery checks. Oil-pump overhaul is expressly excluded: Suzuki directs replacement of a defective pump because internal disassembly can alter its calibrated delivery.

The SRIS hose-arrangement diagram maps the crankcase outlets to the cylinder scavenging passages. Incorrect routing prevents the system from working properly and reduces engine performance.

Charging-System Variants and Ignition Timing

Separate DENSO and KOKUSAN test data cover stator insulation and continuity, rotor condition, brush wear, rectifier function, and regulated output. The interchangeability notes distinguish complete alternator/breaker sets from individual components that cannot be mixed, helping identify compatible parts before replacement.

The special-tool list identifies different rotor removers: 09930-33310 for KOKUSAN and 09930-50951 for DENSO. Ignition timing uses a dial gauge and timing tester; the timing-plate marks are described as an approximate reference.

The contact-breaker camshaft section warns that incorrect handling of the cam fitting nut can break the nylon driven gear.

Forks, Drum Brakes and Routine Inspection

Front-fork procedures cover disassembly and refilling. Brake service includes shoe and drum wear limits and front-brake linkage adjustment. These procedures apply to drum brakes; hydraulic disc-brake service is outside this manual’s scope.

Drive-chain coverage addresses wear measurement, slack adjustment, and the flared joint requiring chain tool 09900-21802. Rear-wheel removal accounts for the mufflers obstructing axle withdrawal.

Component and general-bolt torque tables accompany the periodical inspection list and safety-related component checklist. Steering-stem coverage includes play checks, nut tightening, and fault diagnosis. Brake and steering components require careful inspection before returning the machine to service.

A Preview of Head Torque and Electrical Test Data

Cylinder-head service specifies a set-nut torque of 350 kg-cm (26 lb-ft), accompanied by a tightening-order diagram. The ignition section gives a contact-point gap of 0.35 mm.

For rotor-coil checks between the slip rings, the charging section lists 10.5–11.5 Ω for DENSO and 4–5 Ω for KOKUSAN. These are separate manufacturer-specific test ranges, not a combined tolerance for either rotor.

Printable PDF and Diagram Legibility

Search, navigation and wiring detail: PDF text search and embedded bookmarks are not available. Small switch and terminal labels in the black-and-white wiring diagrams are readable when enlarged. The color version has softer lettering and pale yellow wiring that is harder to follow.

One printable English PDF contains 61 pages: 51 numbered manual pages, one foreword page, two cover pages, one unnumbered additional page, and six appended chart pages. The chart pages comprise one periodical inspection list, two engine exploded-view sheets, and three wiring-diagram versions, all included in the total.