Vehicle Segment:
Classic Air-Cooled Boxer Twin Motorcycle
Historical Competitors:
Moto Guzzi V7/850, Honda CB750/800 (though different engine configuration), Yamaha XS750/850, Kawasaki KZ800.
Motorcycle Design Philosophy:
Robust, reliable, shaft-driven boxer twin engine known for its character, torque, and long-distance touring capabilities. Emphasis on build quality and rider engagement.
Engine Systems:
Engine assembly, disassembly, tuning, carburetion, lubrication, cooling (air-cooled), exhaust systems, cylinder head, pistons, crankshaft, timing.
Transmission And Drivetrain:
Gearbox, clutch, final drive (shaft drive), transmission oil, shifting mechanisms, maintenance, repair.
Chassis And Suspension:
Frame, front forks (telescopic), rear swingarm, shock absorbers, steering head bearings, wheel bearings, suspension adjustments.
Braking System:
Front and rear brakes (likely drum or disc depending on specific R80 variant), brake fluid, hydraulic systems, caliper maintenance, pad replacement, rotor inspection.
Electrical System:
Ignition system (points or electronic), charging system (alternator, regulator), battery, lighting, starter motor, wiring diagrams, component testing.
Fuel System:
Fuel tank, fuel lines, fuel filters, carburetor(s) (e.g., Bing), fuel pump (if equipped), fuel delivery, cleaning, adjustment.
Bodywork And Fittings:
Fenders, seat, fuel tank, side covers, handlebars, controls, instrumentation, exhaust pipes, mufflers.
Maintenance Procedures:
Oil changes, filter replacement, spark plug service, air filter cleaning/replacement, brake adjustments, lubrication points, valve clearance checks/adjustments, tire pressure checks, chain adjustment (if applicable, though R80 is shaft drive).
Troubleshooting Guides:
Diagnostic charts for common starting issues, running problems, electrical faults, braking anomalies, and performance degradation.
Repair Procedures:
Step-by-step instructions for component removal, overhaul, repair, and reinstallation across all covered systems.
Technical Specifications Data:
Torque specifications, tolerances, clearances, fluid capacities, electrical resistance values, and timing settings.
Special Tools Required:
Manual will list any BMW-specific or specialized tools needed for certain repair procedures (e.g., flywheel holding tool, torque wrenches calibrated for metric fasteners).
Depth Of Coverage:
Complete rebuild procedures for engine, transmission, and major components. Detailed diagnostic information for electrical systems and fuel delivery.
Wiring Diagrams Quality:
Detailed electrical schematics and wiring diagrams for all vehicle systems, essential for diagnosing electrical faults.
Engine Type:
Air-cooled, four-stroke, horizontally-opposed (boxer) twin-cylinder
Engine Displacement:
797.5 cc
Bore X Stroke:
83 mm x 74.6 mm
Compression Ratio:
8.2:1 (typical)
Valve Train:
Overhead valves (OHV), pushrod actuated
Horsepower Output:
Approximately 50 hp (37 kW) at 6,000 rpm (approximate, varies by specific model/tuning)
Torque Output:
Approximately 60 Nm (44 lb-ft) at 4,500 rpm (approximate)
Carburetor Configuration:
Twin Bing constant-velocity carburetors (e.g., 32mm or 40mm depending on variant)
Fuel Type Recommendation:
Unleaded gasoline, minimum octane rating 91 (RON+MON)/2
Recommended Engine Oil Viscosity:
SAE 20W-50 or SAE 10W-40 (check manual for ambient temperature suitability)
Engine Oil Capacity With Filter:
Approximately 2.5 liters (2.6 quarts)
Engine Cooling System:
Air cooling
Transmission Type:
5-speed manual transmission
Transmission Gear Ratios:
Specific ratios vary by R80 model (e.g., R80GS, R80RT, R80ST). Manual will detail these.
Recommended Transmission Oil Type:
Hypoid gear oil, API GL-5, SAE 90
Transmission Oil Capacity
Transmission Oil Capacity:
Approximately 0.18 liters (0.19 quarts)
Overall Length:
Varies by model (e.g., R80RT significantly longer than R80G/S). Manual will provide specific dimensions.
Overall Width:
Varies by model. Manual will provide specific dimensions.
Seat Height:
Varies by model. Manual will provide specific dimensions.
Dry Weight:
Approximately 190-210 kg (419-463 lbs) depending on model variant (e.g., R80RT, R80G/S, R80ST).
Fuel Tank Capacity:
Typically 18-20 liters (4.75-5.3 gallons) depending on model variant.
Instrumentation:
Analog speedometer, tachometer (often), odometer, trip meter, indicator lights (neutral, oil pressure, turn signals, high beam). No electronic infotainment systems.
Rider Assistance Features:
None. Focus is on mechanical systems and rider input.
Connectivity Features:
None. This is a pre-digital era motorcycle.
Engine Oil Change Interval:
Every 5,000-10,000 km (3,000-6,000 miles) or annually, whichever comes first. Check manual for specific recommendation.
Valve Clearance Check Interval:
Every 10,000-20,000 km (6,000-12,000 miles). Manual will specify exact interval and procedure.
Final Drive Oil Change Interval:
Every 10,000-20,000 km (6,000-12,000 miles).
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid (depending on system).
Fork Oil Type:
Specific weight SAE fork oil (e.g., SAE 15W or 20W). Manual will detail viscosity and quantity.
Common Maintenance Items:
Regularly inspect and replace spark plugs, air filters, and check ignition points (if applicable). Ensure proper carb synchronization. Shaft drive spline lubrication is critical.
Potential Wear Points:
Steering head bearings, wheel bearings, clutch wear, and fuel line deterioration due to age.
Recommended Parts Consultation:
This service manual will provide part numbers for many common replacement items.
Bmw Motorcycle Legacy:
BMW Motorrad has a long history dating back to the 1920s, renowned for engineering excellence, durable boxer engines, and shaft drive technology.
R Series Development:
The R80 is part of BMW's enduring R-series line, which evolved from the R71 and the iconic R75. The R80 was introduced in the late 1970s as a slightly smaller displacement offering compared to the R100.
R80 Variants:
Key variants include the R80/7 (early model), R80RT (touring), R80ST (sport-touring), and R80G/S (off-road/dual-sport). This manual likely covers one or more of these.
Production Period:
The R80 series was produced from the late 1970s through the 1980s into the early 1990s, with the 1990 model year being a significant part of its production run.
