Target Audience:
Enthusiast owners, independent repair shops, and DIY mechanics working on BMW R80GS and R100R motorcycles.
Value Proposition:
Provides essential technical data and procedures for maintaining and repairing these iconic air-cooled boxer twins, saving significant costs compared to dealership service.
Core Functionality:
Comprehensive guidance for all maintenance, repair, and troubleshooting tasks, ensuring the longevity and optimal performance of the motorcycles.
Engine Mechanical:
Engine disassembly, assembly, cylinder heads, pistons, crankshaft, camshaft, timing, valves, lubrication system, oil pump, oil filter, oil cooler.
Fuel System:
Carburetor (Bing) overhaul, adjustment, fuel tank, fuel lines, fuel pump, fuel filter replacement.
Transmission Drivetrain:
Gearbox disassembly, assembly, troubleshooting, clutch operation, final drive (shaft drive) inspection, maintenance, and repair.
Electrical System:
Ignition system (points/electronic), charging system (alternator, regulator/rectifier), starter motor, battery, lighting system, wiring diagrams, fuses, relays.
Suspension Steering:
Front forks (BMW Monolever system for R100R, telescopic forks for R80GS), rear shock absorbers, swingarm, steering head bearings, steering damper.
Braking System:
Front and rear brake systems (typically Brembo disc brakes), brake fluid replacement, caliper service, master cylinder overhaul, brake line replacement.
Chassis Bodywork:
Frame inspection, seat, fuel tank removal/installation, fenders, fairings (if applicable), exhaust system, footpegs, handlebars.
Maintenance:
Oil changes, filter replacements, spark plug service, air filter cleaning/replacement, chain adjustment (if applicable), valve clearance checks/adjustments, brake bleeding, fork oil changes.
Troubleshooting:
Systematic diagnostic procedures for common problems related to engine performance, starting issues, electrical faults, braking performance, and suspension.
Repair Rebuild:
Detailed step-by-step instructions for major component repairs and complete overhauls of the engine, transmission, and other critical systems.
Wiring Diagrams:
Comprehensive electrical schematic diagrams for easy identification and repair of electrical system faults.
Diagnostic Capabilities:
Advanced diagnostic procedures, including specifications for measurements, tolerances, and troubleshooting charts.
Rebuild Specifications:
Torque specifications, clearances, and rebuild procedures for all major mechanical components.
Engine Type:
Air-cooled, four-stroke, boxer-twin (flat-twin) engine
Engine Displacement R80Gs:
797.5 cc (approx.)
Engine Displacement R100R:
979.7 cc (approx.)
Bore X Stroke R80Gs:
82.5 mm x 74.5 mm (approx.)
Bore X Stroke R100R:
94 mm x 74.5 mm (approx.)
Horsepower R80Gs:
Around 50-55 hp (varies slightly by specific model year/tuning)
Horsepower R100R:
Around 60-65 hp (varies slightly by specific model year/tuning)
Torque R100R:
Around 75 Nm (approx. at 4500 rpm)
Carburetor Type:
Dual Bing constant velocity carburetors (e.g., 32mm or 40mm depending on model/year)
Fuel Type:
Unleaded gasoline (91 octane RON recommended)
Wheelbase R80Gs:
Approx. 1450 mm (57.1 in)
Wheelbase R100R:
Approx. 1465 mm (57.7 in)
Seat Height R80Gs:
Approx. 820 mm (32.3 in)
Seat Height R100R:
Approx. 810 mm (31.9 in)
Dry Weight R80Gs:
Approx. 185 kg (408 lbs)
Dry Weight R100R:
Approx. 195 kg (430 lbs)
Fuel Tank Capacity R80Gs:
Approx. 19 Liters (5.0 US gal)
Fuel Tank Capacity R100R:
Approx. 26 Liters (6.9 US gal) for R100R Paris-Dakar / Classic
Oil Change Interval:
Typically every 5,000 - 10,000 km (3,000 - 6,000 miles) or annually, depending on usage. Verify with manual.
Valve Clearance Check:
Typically every 10,000 - 20,000 km (6,000 - 12,000 miles). Crucial for boxer engine health.
Spark Plug Replacement:
As per manual recommendations, often around 10,000 - 20,000 km.
Engine Oil Type:
BMW recommends specific grades of mineral or semi-synthetic oils, typically SAE 20W-40, 20W-50, or 10W-40 depending on climate. Verify with manual.
Engine Oil Capacity:
Approximately 2.0 - 2.5 liters (check manual for exact capacity with filter change).
Brake Fluid Type:
DOT 4 or DOT 5.1 (check manual for specific recommendation).
Fork Oil Type:
Typically a 10W or 15W fork oil, with specific viscosity and quantity detailed in the manual.
General Wear Items:
Cam chain wear, output shaft seal leaks, clutch wear, fork seal leaks, steering head bearing play, aging electrical connectors.
R100R Specific:
Potential for transmission input shaft seal leaks, aging rubber fuel lines.
R80Gs Specific:
Paralever pivot bearing wear (on later models), swingarm bearing wear.
Bmw Motorrad Legacy:
BMW Motorrad has a long history of producing robust and reliable motorcycles, particularly known for their boxer engines and shaft drive systems since the early 20th century.
R80Gs Development:
The R80GS, introduced in 1980, pioneered the 'adventure touring' or 'dual-sport' motorcycle segment, combining road manners with off-road capability. The R80GS covered here is a later iteration of this iconic model.
R100R Development:
The R100R, launched in 1991, represented a refinement of BMW's established R-series boxer platform, offering improved styling and performance, often considered a 'roadster' or 'cruiser' variant compared to the GS.
Production Period:
The specified models were produced within the period 1988-1994, representing the later stages of the R80GS and the initial production run of the R100R series.
