Honda CB900C / CB900F 1979–1983 Service Manual Set

The CB900F addendum supplements the base procedures with model-specific service information. The appended jet-kit instructions are separate aftermarket reference material, not Honda service-publication pages.

Coverage limits: The base Section 12 – Transmission, standalone Section 23 – Troubleshooting, ’81 CB900C Addendum, and ’82 CB900C·F Addendum listed in the original contents are absent. Section-level troubleshooting is included throughout many of the supplied chapters.

PDF Search, Bookmarks and Wiring Detail

Search and navigation: Honda service pages do not support PDF text search; only the final jet-kit instruction pages are searchable. Embedded bookmarks link to chapters, the addendum, and the jet-kit sheet, although some labels are inaccurate and the clutch bookmark opens the repeated chapter. Small wiring labels require zooming.

One printable, English-language 367-page PDF contains all three publications. That total includes 14 duplicated clutch-chapter pages, the blank page following the addendum, and the two appended jet-kit instruction pages.

Engine, Driveline and Electrical Service

The following selected service topics outline the main workshop coverage rather than reproduce the full contents. Other included subjects include crankcase-breather maintenance and headlight-aim adjustment.

• Engine repair: Step-by-step procedures for engine removal, camshaft and cylinder-head service, valve-guide replacement, valve-seat refacing, and cylinder/piston inspection.

• Lubrication: Oil-pressure testing, oil-pump disassembly and inspection, oil-cooler checks, strainer cleaning, and CB900C subtransmission oil-pump service.

• Carburetors: Removal, bank separation and reassembly, float-level setting, synchronization, fast-idle adjustment, and the pilot-screw idle-drop procedure.

• Clutch and driveline: Clutch, starter-clutch and gearshift-linkage service, plus CB900C subtransmission disassembly, seal replacement, and final-drive backlash and preload checks.

• Suspension and wheels: Front-fork disassembly, seal and bushing inspection, steering-stem service, wheel-bearing replacement, rear-shock service, and swingarm work.

• Hydraulic brakes: Fluid replacement and bleeding, pad/disc inspection, master-cylinder service, and caliper disassembly, measurement and reassembly.

• Electrical diagnosis: Battery/charging tests, ignition checks, starter-motor inspection, switch-continuity tests, and CB900C rear-suspension air-pressure warning-system troubleshooting.

The manual suits mechanically qualified owners with proper tools and service data; Honda recommends authorized-dealer service for the maintenance schedule’s specially marked safety items.

Model Identification and Configuration Differences

Frame references distinguish the CB900C beginning with SC04-2000046, its Canadian version beginning with SC04-2001669, and the ’81 CB900F beginning with SC010-0000021 before parts or repair procedures are selected.

The CB900C material covers the dual-range subtransmission and shaft final drive; the CB900F addendum addresses the chain-drive configuration. Its model-specific dimensions, engine, carburetion, drivetrain and electrical specifications accompany torque tables and Cable & Harness Routing views.

Engine Inspection and Service Tools

The Crankshaft/Primary Shaft chapter includes connecting-rod work, primary-chain tensioner service, color-coded bearing selection, and Plastigauge clearance checks. The Engine Lubrication Diagram and Valve Shim Selection Chart support oil-circuit tracing and shim selection.

Tool references include valve lifter holder 07964-4220001, primary gear holder 07924-4250000, and clutch center holder 07923-3710000. The CB900F addendum also provides a revised valve-shim adjustment procedure.

Honda warns that incorrect valve-lifter-holder positioning or crankshaft rotation during the base valve-shim procedure can allow intake and exhaust valves to strike and damage each other.

Carburetor Components and Adjustment

Fuel-system detail extends to vacuum cylinders, pilot screws, floats and jets, air-cutoff valves, accelerator-pump components, and throttle/choke linkage. These component checks accompany the adjustment procedures rather than stop at routine maintenance specifications.

The carburetor cautions address pilot-screw seat damage from overtightening and joint-pipe or choke-linkage damage during incorrect bank separation.

Shaft-Drive Setup and Suspension Differences

The Dual Range Subtransmission power-flow illustration and Shaft Drive layout explain the CB900C driveline. The documented reduction ratios are 0.638 in high range and 0.721 in low range; the subtransmission takes 0.6 L of SAE 80 hypoid gear oil.

Final-drive lubrication calls for 150 cc of API GL-5 hypoid oil, with SAE 90 above 5°C/41°F or SAE 80 below that temperature. The service chapter covers backlash measurement, oil seals, O-rings, and pinion/ring-gear preload adjustment.

Subtransmission setups identify damper compressor 07964-4610000 and preload inspection tool 07998-4610000. Honda marks certain fixtures as unavailable in the U.S.A. and specifies assembly replacement when the subtransmission bearings or drive/driven gears require replacement.

The CB900F suspension pages cover VHD shock spring removal, inspection, and preload/rebound/compression adjustment. They prohibit further disassembly of the shock damper.

Charging, Ignition and Circuit Tracing

Electrical material covers the A.C. generator, stator/rotor, regulator/rectifier, spark units, pulser generator, electric starter, and switch circuits. The CB900C rear-suspension warning-system charts distinguish lamp, wiring, sensor, and control-unit faults.

The ’81 CB900F Wiring Diagram is included in original and revised sheets, supporting connector identification and wire-color tracing alongside the electrical tests.

For system-opening repair work, follow Honda’s component-specific safety notes. Brake fluid must be kept off painted surfaces, and the manual calls for battery-ground disconnection during applicable engine and electrical service.

A Preview of Oil, Valve and Ignition Specifications

Oil service: The lubrication chapter lists 3.5 L (3.7 US qt) at an oil change and 4.5 L (4.7 US qt) after disassembly. Oil-pressure testing specifies 5.5 kg/cm² (78 psi) at 7,000 rpm with oil at 80°C/176°F, using gauge attachment 07510-4220100.

Valve and plug settings: Intake and exhaust valve clearance is 0.06–0.13 mm (0.002–0.005 in) with the engine cold, below 35°C/95°F. Spark-plug gap is 0.6–0.7 mm (0.024–0.028 in).