1991 Ducati 750 & 900 SuperSport Workshop Manual (P/N 914.7.006.1B)

This Ducati workshop manual covers the 1991 750 SuperSport and 900 SuperSport, identified as 750 S.S. and 900 S.S. throughout the text. It is the first edition, Print No. 914.7.006.1B, dated April 1991, for these carbureted, air-cooled models.

• Engine repair and Desmodromic timing: Engine removal, cylinder-head disassembly, valve-train inspection, valve-clearance adjustment, timing-belt replacement, and pulley alignment.

• Clutch and gearbox: Dry-clutch disassembly and reassembly, gearbox-shaft inspection, shift-fork checks, and hydraulic clutch-release service.

• Fuel system: Mikuni BDST carburetor specifications, synchronization and idle adjustment, component inspection, and circuit-based troubleshooting.

• Suspension and wheels: Showa fork service, swingarm inspection, steering-head bearing replacement, and Brembo alloy-wheel removal and bearing checks.

• Brakes: Brembo caliper and master-cylinder overhaul, disc and pad inspection, fluid replacement, and hydraulic bleeding.

• Electrical diagnosis: Kokusan ignition resistance and advance checks, charging and starting fault diagnosis, and wiring diagrams.

Written for authorized Ducati workshop personnel, this manual assumes mechanical experience and access to the specified measuring equipment and special tools.

Engine Overhaul, Valve Timing, and Clutch Variants

The engine chapters move from disassembly through component inspection to reassembly. They cover cylinder and piston class matching, connecting-rod bearings, crankshaft inspection, and gearbox endplay. Separate clutch procedures distinguish the two models, including two friction-disc configurations for the 750 S.S.

Desmodromic service includes rocker-arm shimming and valve-adjuster selection. The timing instructions warn that reused pulley locknuts can loosen and cause serious engine damage. Tool references include timing-belt tensioner 88713.0748 and clutch-drum holding wrench 88713.0146.

Lubrication work covers oil-pump inspection and removal of the 900 S.S. oil cooler and its lines. Exhaust-manifold removal is included in the engine-access procedures.

Mikuni Carburetor Adjustment and Fault Diagnosis

Calibration tables distinguish the Mikuni BDST 38-B70 on the 750 S.S., BDST 38-B67 on the 900 S.S., and BDST 38-B73 on the 900 S.S. USA. Synchronization and idle-adjustment procedures use vacuum balancing and exhaust-gas analysis.

The carburetor chapter explains float, pilot, transition, and main-metering circuits, supported by component section views and an operating-range chart. Its links between CO/HC readings and circuit faults help narrow down off-idle hesitation and rich or lean running.

Showa Suspension, Brembo Brakes, and Chassis

The detailed internal fork-overhaul procedure applies to the 900 S.S. Showa GD011. The 750 S.S. GD031 has its own specifications; the step-by-step rebuild section is specifically for the GD011. Suspension coverage also includes rebound and compression settings, rear-shock adjustment, and model-specific swingarm bearings or bushings.

Brembo caliper exploded views distinguish P4 32d and P4 30/34 assemblies. The serial-number change identifies the relevant front-caliper configuration before seals and pistons are selected. Hydraulic clutch layouts distinguish the right-side actuator on the 750 S.S. from the left-side arrangement on the 900 S.S.

Dimensioned drawings cover the chrome-molybdenum trellis frame. Maintenance schedules and service tables provide fluid capacities, spark-plug specifications, tire pressures, chain dimensions, final-drive and internal gear ratios, and engine/chassis fastener torques.

The manual's brake and fuel-system precautions address harmful brake-fluid contact, paint damage, and ignition of gasoline vapors.

Kokusan Ignition and Charging-System Checks

Electrical coverage includes alternator-rotor removal, regulator-rectifier fault checks, and starter-motor removal and connection checks. The main wiring schematic and separate ignition-system diagram include component references and wire color codes.

The regulator section warns that disconnecting the battery while the engine runs can permanently damage the regulator.

A Preview of Valve-Clearance and Ignition Test Data

These examples are a small selection of the manual's valve-adjustment and electrical test specifications.

For both models, the cold intake opening-rocker clearance is 0.08–0.10 mm. This is distinct from the closing-rocker clearance covered in the valve-adjustment procedures.

Ignition checks specify 0.34 ohm ±10% for the coil's low-voltage circuit and 100 ohms ±5% for the pickup.

PDF Bookmarks, Diagram Detail, and Included Pages

Search, navigation, and wiring detail: PDF text search is unavailable. Embedded chapter bookmarks and printed analytical indexes provide navigation. Small wiring labels require zooming; the main wiring schematic spans two PDF pages.

One printable 348-page PDF contains English, Italian, French, German, and Spanish text. The total includes 10 pages of cover and introductory material and 10 blank pages; the remaining 328 pages contain the manual's chapters, tables, diagrams, and indexes.