Segment:
BMW's 'large displacement' boxer-twin motorcycle line, renowned for touring, sport-touring, and adventure capabilities.
Competitors:
Competed with other large-displacement motorcycles of the era, but held a unique position due to its boxer engine layout and engineering excellence (e.g., Honda GL series, Moto Guzzi V-twin models).
Engine Layout:
Air-cooled, horizontally opposed twin-cylinder boxer engine.
Heritage:
Successor to earlier iconic BMW boxers, embodying the brand's tradition of quality, durability, and innovation in motorcycle engineering.
Covered Years:
1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
Estimated Page Count:
Variable, typically 400-800+ pages depending on specific publication and model year inclusion.
Type:
Workshop Service Manual (WSM) / Repair Manual
Format:
Digital (likely PDF, potentially with searchable text)
Engine:
Full engine overhaul, top-end (cylinder head, valves, camshafts), bottom-end (crankshaft, connecting rods, pistons), timing chain, lubrication system (oil pump, oil cooler, oil filter), fuel system (carburetors, fuel lines, fuel pump), ignition system (spark plugs, ignition coils, control unit).
Transmission:
Gearbox disassembly and assembly, clutch operation and adjustment, gear selection mechanism, final drive (bevel gear housing, driveshaft, universal joint), gearbox oil.
Chassis And Frame:
Frame inspection and repair, steering head bearing maintenance, swingarm and pivot bearings, side stand and center stand.
Suspension:
Front forks (oil change, seal replacement, spring replacement, damping adjustments), rear shock absorbers (maintenance, adjustment, replacement), linkages.
Brakes:
Hydraulic brake system (master cylinder, brake lines, calipers, brake pads, brake discs), bleeding procedures, brake fluid specifications.
Electrical System:
Wiring diagrams for all models, battery maintenance, charging system (alternator, regulator/rectifier), starter motor, lighting system (headlight, taillight, turn signals), instrumentation, horn, fuses.
Fuel System:
Carburetor identification (e.g., Bing 32/40), synchronization, jetting, float height adjustment, fuel filter replacement, fuel tank maintenance.
Cooling System:
Air-cooled engine specifics, oil cooling system components and maintenance.
Bodywork And Trim:
Fairing removal and installation (if applicable, e.g., R100RS, R100RT), tank and seat removal, fender replacement, minor body panel repairs.
Routine Maintenance:
Oil and filter changes, spark plug replacement, air filter cleaning/replacement, valve clearance adjustment, carburetor synchronization, brake fluid flush, gearbox and final drive oil changes, battery check.
Troubleshooting:
Diagnostic procedures for common starting, running, and electrical issues, symptom-based problem solving.
Major Repairs:
Complete engine rebuild procedures, transmission overhaul, fork rebuild, brake caliper overhaul, wheel bearing replacement.
Special Tools:
Identification and usage of specific BMW special tools required for various maintenance and repair tasks.
Depth:
Comprehensive, from basic owner maintenance to full engine and transmission rebuilds. Includes detailed specifications, tolerances, and torque values.
Configuration:
Horizontally opposed twin-cylinder (boxer)
Displacement:
980 cc (970.9 cc actual)
Bore X Stroke:
94 mm x 70.6 mm
Compression Ratio:
Typically 8.5:1 or 9.5:1 depending on sub-model and year.
Valve Train:
Overhead camshaft (OHC), pushrod actuated valves (OHV) in some earlier variants, but OHC with pushrods driving rocker arms is more common for R100.
Horsepower:
Approximately 65-70 hp @ 7000-7500 rpm (varies by model).
Torque:
Approximately 56-60 lb-ft @ 5500-6000 rpm (varies by model).
Carburetors:
Typically twin Bing constant-velocity carburetors (e.g., 32/40mm or 40mm depending on model).
Fuel Type:
Unleaded gasoline (RON 91 or higher recommended).
Fuel Delivery:
Mechanical fuel pump.
Oil Change:
Typically every 3,000-6,000 miles (5,000-10,000 km) or annually. Check manual for exact interval.
Valve Adjustment:
Every 6,000-12,000 miles (10,000-20,000 km).
Spark Plug Replacement:
Every 6,000-12,000 miles (10,000-20,000 km).
Carburetor Sync:
Every 6,000-12,000 miles (10,000-20,000 km) or as needed for smooth running.
Engine Oil:
SAE 20W-50 or SAE 10W-40 motorcycle-specific oil with API SF or SG classification. Check manual for precise viscosity based on climate.
Gearbox Oil:
Hypoid gear oil, SAE 80W-90 (API GL-5).
Final Drive Oil:
Hypoid gear oil, SAE 80W-90 (API GL-5).
Brake Fluid:
DOT 4 hydraulic brake fluid (hygroscopic, requires periodic replacement).
Fork Oil:
Specific weight fork oil, typically SAE 10W or 15W. Consult manual for exact type and quantity.
Common Problems:
Oil leaks (especially from pushrod tubes and base gaskets), alternator brushes wear, carburetor synchronization drift, clutch pushrod seal leaks, final drive spline wear, starter motor solenoid issues.
Repair Solutions:
Manual provides detailed procedures for addressing leaks (gaskets, seals), brush replacement, carburetor tuning, and spline lubrication/replacement.
Legacy:
BMW Motorrad's long history of producing reliable, high-quality motorcycles, particularly known for its boxer-twin engine platform.
Development:
The R100 series represents an evolution of BMW's boxer engine, building upon successful predecessors like the R75/5, R90/6, and R100/7. It saw various iterations catering to different riding styles (sport, touring, dual-sport).
Manufacturing Period:
1976-1996 (though this manual covers 1978-1996, the R100 engine platform was in production earlier and continued slightly later in certain forms).
Key Variants:
R100/7, R100S, R100CS, R100RT, R100RS, R100GS, R100R. Each variant offered different styling, equipment, and intended use.
