Model:
R Series (R80, R90, R100)
Model Variants:
R80/7, R80RT, R80G/S, R80ST, R90/6, R90S, R100/7, R100S, R100CS, R100RT, R100RS, R100GS, R100R, R100GS PD
Production Years:
1978-1996
Engine Code General:
Type 247 (Airhead Boxer Engine)
Motorcycle Segment:
Heritage Boxer Twin, Touring, Sport Touring, Dual-Sport
Target Audience:
Owners of BMW R80, R90, and R100 series motorcycles seeking to perform their own maintenance and repairs, restorers, and enthusiasts.
Competitors Era:
Moto Guzzi V-twins, Honda CB series, Kawasaki Z series, Yamaha XS series, Ducati Bevel-Drive twins.
Engine Layout:
Air-cooled, horizontally-opposed twin-cylinder (Boxer) engine
Drivetrain:
Shaft drive, leading to low maintenance and clean aesthetic.
Handling:
Known for stable and predictable handling characteristics, particularly the 'monolever' and 'paralever' rear suspension models.
Comprehensiveness:
Covers a wide range of model years and variations within the R80, R90, and R100 families.
Technical Accuracy:
Based on factory service data, ensuring accurate repair procedures and specifications.
Engine Mechanical:
Complete teardown, assembly, inspection, and repair of all internal engine components (pistons, rings, cylinders, crankshaft, camshaft, valves, timing chain/gears, lubrication system).
Engine Fuel System:
Carburetor (Bing) tuning, overhaul, jetting, float adjustment, fuel pump, fuel lines, fuel tank inspection and cleaning.
Engine Ignition System:
Ignition timing, points and condenser (if applicable), electronic ignition systems (Motoplat, Boyer Bransden, etc.), spark plugs, coils, high-tension leads.
Transmission:
Gearbox disassembly, assembly, inspection, gear selection, clutch operation (single plate dry clutch, dual plate wet clutch on some models), transmission fluid changes, troubleshooting.
Drivetrain:
Shaft drive system inspection, universal joint maintenance, final drive unit service, gear ratio information.
Brakes:
Hydraulic brake system servicing (master cylinders, calipers, brake lines, fluid flush and bleed), brake pad inspection and replacement, drum brake adjustment (rear on some models), parking brake system.
Suspension:
Front fork servicing (oil changes, seal replacement, spring inspection), rear shock absorber service and adjustment, swingarm and pivot bearing maintenance.
Electrical System:
Wiring diagrams, component testing (alternator, starter motor, battery, lighting, horn, instrumentation), fuse box layout, troubleshooting electrical faults.
Chassis And Frame:
Frame inspection, steering head bearing maintenance and adjustment, wheel bearing service, sidestand and centerstand service.
Bodywork And Fairings:
Body panel removal and installation, seat maintenance, fuel tank removal, fairing component repair and replacement (where applicable).
Routine Maintenance:
Oil changes, filter replacement, spark plug replacement, chain adjustment (if applicable, though most are shaft drive), lubrication points, tire pressure checks.
Troubleshooting:
Diagnostic flowcharts and common problem identification for engine, electrical, and mechanical systems.
Repair Procedures:
Step-by-step instructions for component removal, overhaul, and reinstallation for all major vehicle systems.
Performance Tuning:
Carburetor synchronization and tuning, ignition timing adjustments, advice on performance upgrades (though primarily focused on stock specifications).
Overhaul Instructions:
Detailed guides for complete engine and transmission rebuilds.
Diagnostic Capabilities:
Advanced diagnostic procedures for electrical systems, including resistance measurements, voltage checks, and continuity testing.
Torque Specifications:
Precise torque values for all critical fasteners throughout the motorcycle.
Clearances And Tolerances:
Specifications for valve clearances, piston-to-cylinder clearance, bearing clearances, and other critical engine tolerances.
Wiring Diagrams:
Comprehensive and clear electrical wiring diagrams for all applicable models and variations.
Special Tool Requirements:
Identification of specialized tools required for certain repair and maintenance procedures.
Engine Type:
Four-stroke, horizontally opposed twin-cylinder (Boxer), air-cooled
Displacement R80:
797.5 cc (approx.)
Displacement R90:
897.1 cc (approx.)
Displacement R100:
979.1 cc to 1046.6 cc (depending on specific R100 model)
Horsepower R80:
Approx. 50 hp (Varies by sub-model and year)
Horsepower R90:
Approx. 60-70 hp (Varies by sub-model, especially R90S)
Horsepower R100:
Approx. 65-70 hp (Varies by sub-model and year)
Torque R80:
Approx. 56 Nm (Varies)
Torque R90:
Approx. 70 Nm (Varies)
Torque R100:
Approx. 75-80 Nm (Varies)
Carburetors:
Typically dual Bing constant-velocity carburetors (e.g., 32mm, 36mm, 40mm depending on model and year)
Fuel Type:
Unleaded gasoline (minimum 90 RON / 87 AKI)
Fuel Tank Capacity:
Typically 17-24 liters (4.5-6.3 US gallons)
Oil Change Interval:
Typically every 5,000 - 10,000 km (3,000 - 6,000 miles) or annually, depending on usage and manual recommendations.
Valve Adjustment Interval:
Typically every 10,000 - 20,000 km (6,000 - 12,000 miles), depending on model and manual. This is a crucial maintenance item for these engines.
Spark Plug Replacement:
Every 10,000 - 20,000 km (6,000 - 12,000 miles).
Brake Fluid Flush:
Every 1-2 years.
Engine Oil Type:
SAE 20W-40 or 20W-50 API SG or higher. Manual will specify exact viscosity based on ambient temperature.
Engine Oil Capacity:
Approx. 2.5 - 3.0 liters (2.6 - 3.2 US quarts) with filter change.
Transmission Oil Type:
SAE 80W-90 API GL-5 hypoid gear oil.
Transmission Oil Capacity:
Approx. 0.8 - 1.0 liter (0.8 - 1.1 US quarts).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid (check manual for specific recommendation).
Fork Oil Type:
Specific weight fork oil, e.g., SAE 15W or 20W, depending on model and desired damping characteristics. Manual provides precise specifications.
Common Issues Engine:
Oil leaks (especially around oil pan, crank seal, and pushrod tubes), worn valve guides, cam follower wear, clutch wear, carburetor icing (on older models in cold weather), timing chain stretch.
Common Issues Electrical:
Ignition switch failures, charging system issues (rotor, regulator), starter solenoid problems, aging wiring harnesses.
Common Issues Chassis:
Worn steering head bearings, swingarm pivot wear, aging rubber components (hoses, seals), corrosion on frame and bodywork.
Bmw Motorcycle Legacy:
BMW has a long and distinguished history in motorcycle manufacturing, dating back to the 1920s, with a strong reputation for engineering, reliability, and touring capabilities.
R Series Lineage:
The R80, R90, and R100 models represent the evolution of BMW's air-cooled boxer twin motorcycle line, building upon the success of earlier models like the R75/5 and R90/6. The R100 series, in particular, saw advancements like the 'Monolever' (single-sided swingarm and driveshaft enclosure) and 'Paralever' (improved rear suspension geometry).
Manufacturing Location:
Berlin, Germany (Spandau plant)
Key Innovations Era:
Introduction of Monolever and Paralever rear suspension, advancements in braking systems (Brembo discs), and refined engine designs for increased power and reliability.
