Target Audience:
Owners and mechanics of vintage BMW Airhead motorcycles seeking detailed repair and maintenance information.
Manual Value:
Provides factory-level accuracy and detail often superior to aftermarket manuals.
Completeness:
Covers all major mechanical and electrical systems specific to the 1979 R80, R90, and R100 models.
Print Flexibility:
Allows users to print the entire manual or specific sections as needed.
Systems Covered:
Engine, Transmission, Drivetrain, Chassis, Electrical System, Fuel System, Brake System, Suspension, Bodywork, Tools & Equipment, Troubleshooting.
Type:
Factory Service Repair Manual
Engine Overhaul:
Detailed procedures for engine disassembly, inspection, repair, and reassembly for all boxer twin variants.
Transmission Service:
Comprehensive guides on gearbox removal, inspection, component replacement, and adjustment.
Drivetrain Maintenance:
Shaft drive system maintenance, universal joint inspection, and final drive unit servicing.
Electrical Diagnostics:
Wiring diagrams, troubleshooting guides for ignition, lighting, charging systems, and starter motor.
Fuel System Repair:
Carburetor (Dell'Orto/Bing) adjustment, rebuilding, fuel tank and line maintenance, and fuel pump operation.
Brake System Overhaul:
Disc brake pad replacement, caliper servicing, brake fluid bleeding, and drum brake adjustments (if applicable).
Suspension Geometry:
Front fork (telescopic) servicing, rear shock absorber replacement, and steering head bearing adjustment.
Bodywork Restoration:
Panel removal and installation, fairing (if equipped) repair, seat and tank mounting procedures.
Ignition System:
Points, condenser, coil, and spark plug troubleshooting and adjustment.
Routine Maintenance:
Oil changes, filter replacements, spark plug checks, valve clearance adjustments, carburetor synchronization.
Troubleshooting Guides:
Systematic diagnostic procedures for common and uncommon problems.
Rebuilding Procedures:
Complete step-by-step guides for major component overhauls.
Technical Data Tables:
Torque specifications, clearances, fluid capacities, electrical resistance values.
Electrical Schematics:
Detailed, factory-quality wiring diagrams for all electrical components.
Torque Specs:
Comprehensive torque specifications for all critical fasteners.
Depth Of Coverage:
Comprehensive, covering from basic rider maintenance to full engine and gearbox rebuilds, suitable for professional mechanics and skilled DIY enthusiasts.
Diagnostic Tools:
Includes instructions for using specialized BMW tools where applicable.
Engine Type:
Air-cooled, four-stroke, boxer-twin cylinder
Displacement R100:
980 cc
Bore X Stroke R80:
82.5 mm x 74.5 mm
Bore X Stroke R90:
90 mm x 70.6 mm
Bore X Stroke R100:
94 mm x 70.6 mm
Compression Ratio Typical:
8.2:1 to 9.5:1 (model dependent)
Carburetor Type:
Dual Bing constant velocity carburetors (e.g., 32/36/40/42mm) or Dell'Orto
Fuel Type:
Unleaded gasoline (87 octane or higher)
Fuel Delivery:
Gravity feed from fuel tank, electric or mechanical fuel pump (model dependent)
Oil Type:
SAE 20W-50 or SAE 10W-40 motorcycle specific oil
Oil Capacity Approx:
2.5 - 3.0 liters (including filter)
Gearbox Type:
5-speed constant mesh, sequential manual transmission
Final Drive:
Shaft drive (single universal joint)
Clutch Type:
Single dry plate, diaphragm spring clutch
Gear Ratios:
Specific ratios vary by model, detailed in manual
Oil Change Interval:
Every 5,000 - 10,000 km or annually, whichever comes first (refer to manual for specifics).
Valve Adjustment Interval:
Every 10,000 - 20,000 km (manual provides precise figures).
Carburetor Sync Interval:
As needed, typically every 10,000 - 20,000 km or if performance issues arise.
Transmission Oil Type:
SAE 75W/90 or SAE 80W/90 API GL-5 gear oil
Final Drive Oil Type:
SAE 75W/90 or SAE 80W/90 API GL-5 gear oil
Brake Fluid Type:
DOT 3 or DOT 4 (ensure compliance with original specifications)
Common Wear Items:
Clutch wear, output shaft seal leaks, charging system (rectifier/regulator) issues, carburetor needle wear.
Prevention Tips:
Regular maintenance as per manual, proper warm-up procedures, and avoiding over-revving.
Bmw Motorrad Legacy:
BMW Motorrad's reputation for durable, reliable, and technologically advanced motorcycles.
Airhead Development:
Evolution of BMW's iconic boxer twin (Airhead) platform, emphasizing touring comfort and reliability.
Manufacturing Era:
These models represent a significant period in BMW's motorcycle manufacturing, building on decades of experience.
