Vehicle Segment:
Adventure Touring / Roadster (depending on specific model variant)
Target Audience:
Owners seeking to perform their own maintenance and repairs, enthusiasts, independent workshops.
Key Competitors:
Honda VFR800, Triumph Tiger 955i, Ducati Multistrada 1000 (for GS variant); Honda CB900F, Triumph Bonneville (for R variant).
Manual Benefit:
Significant cost savings on dealership servicing and repairs.
Manual Utility:
Enables owners to maintain their motorcycles to factory standards, prolonging lifespan and preserving value.
Engine Mechanical:
Complete overhaul, top-end (cylinder heads, valves, camshafts), bottom-end (crankshaft, con-rods, bearings), timing, oil pump, lubrication system.
Engine Management:
Fuel injection system (throttle body, injectors, sensors - O2, MAP, TPS), ignition system (spark plugs, coils, ECU), starting system (starter motor, solenoid), charging system (alternator, regulator/rectifier).
Transmission Drivetrain:
Clutch (operation, adjustment, replacement), gearbox (gear selection, maintenance, overhaul), final drive (bevel gear, driveshaft, U-joint inspection).
Chassis Suspension:
Front forks (telescopic, seals, oil, adjustment), rear shock absorber (MonoLever or Paralever system, adjustment, rebuild), wheel bearings, steering head bearings.
Brakes:
Front and rear brake systems (discs, calipers, master cylinders, brake lines), ABS system (if equipped), bleeding procedures, pad replacement, rotor specifications.
Electrical System:
Wiring diagrams, component testing (lights, horn, indicators), battery maintenance, fuse box layout, diagnostic connectors.
Fuel System:
Fuel tank, fuel pump, fuel filter, fuel lines, EFI system diagnostics.
Bodywork Fittings:
Fairings, seat removal, tank removal, luggage systems (attachment points), fenders.
Routine Maintenance:
Oil and filter changes, spark plug replacement, air filter cleaning/replacement, chain/driveshaft lubrication, brake fluid flush, coolant flush.
Troubleshooting:
Diagnostic flowcharts for common starting, running, electrical, and braking issues.
Component Overhaul:
Detailed step-by-step instructions for rebuilding engine components, gearboxes, and suspension units.
Wiring Diagrams:
Comprehensive electrical schematics for all systems.
Torque Specifications:
Critical torque values for all fasteners during assembly and disassembly.
Special Tools:
Identification and use of specialized BMW tools required for specific procedures.
Level Of Detail:
Comprehensive (from basic maintenance to complete engine and gearbox rebuilds).
Diagnostics:
Includes diagnostic procedures for EFI and ignition systems, component testing.
Repair Procedures:
Detailed, illustrated step-by-step repair instructions for all major vehicle systems.
Engine Type:
Air/oil-cooled, four-stroke, flat-twin (Boxer) engine
Displacement:
848 cc (848 cubic centimeters)
Bore X Stroke:
90.5 mm x 66 mm
Compression Ratio:
10.0:1
Valve Train:
2 valves per cylinder, OHC (Overhead Camshaft)
Power Output Ps:
Approx. 70-72 PS (51-53 kW) @ 7,500 rpm (model dependent)
Power Output Hp:
Approx. 70-72 hp (model dependent)
Torque:
Approx. 75-77 Nm (55-57 lb-ft) @ 5,500 rpm (model dependent)
Top Speed Gs:
Approx. 180 km/h (112 mph)
Top Speed R:
Approx. 185 km/h (115 mph)
Fuel Delivery:
Electronic Fuel Injection (BMW Synthesized Fuel Injection - BMS-K variant typical)
Fuel Type:
Unleaded gasoline, minimum 95 RON
Fuel Capacity:
Approx. 25 Liters (6.6 US gal) for R850GS, 20 Liters (5.3 US gal) for R850R
Oil Change Interval:
Typically every 10,000 km (6,200 miles) or annually, whichever comes first (refer to manual for exact spec).
Valve Clearance Check:
Typically every 20,000 km (12,500 miles) or annually (refer to manual for exact spec).
Spark Plug Replacement:
Typically every 20,000 km (12,500 miles) or as needed (refer to manual for exact spec).
Driveshaft Service:
Lubrication and inspection at recommended intervals (refer to manual).
Engine Oil Type:
BMW recommends synthetic engine oil, viscosity typically 15W-50 or 20W-50 (API SG/SH or higher, JASO MA compliant for wet clutch).
Engine Oil Capacity:
Approx. 3.0 Liters (3.2 US quarts) with filter change.
Brake Fluid Type:
DOT 4 recommended.
Coolant Type:
Ethylene glycol-based coolant with corrosion inhibitors (BMW recommended).
Common Wear Items:
Clutch wear, wheel bearings, steering head bearings, exhaust system (rust/leaks), fuel pump issues, alternator/regulator failures.
Electrical Gremlins:
Occasional issues with wiring harness connections, especially in connectors subjected to vibration and moisture.
Fuel Injector Clogging:
Can occur with poor fuel quality or age, requiring cleaning or replacement.
Manufacturer:
Bayerische Motoren Werke AG (BMW), Germany
Motorcycle Focus:
BMW has a long and distinguished history in motorcycle production, known for its boxer engines and touring capabilities.
Series Origin:
The R850 series is a derivative of the larger R1100/R1150 boxer twins, offering a more accessible displacement and price point.
Gs Variant:
The R850GS is the adventure-oriented variant, featuring longer suspension travel, spoked wheels, and a higher riding position compared to the R850R.
R Variant:
The R850R is the roadster/naked variant, emphasizing comfortable urban and touring use.
Manufacturing Location:
Berlin Spandau, Germany
Production Period:
The R850 series was produced from the late 1990s through the mid-2000s, with this manual covering the 2000-2005 range.
