🏷️ Basic Information

Make:

BMW

Model:

R1100RT, R1100RS, R850GS, R1100GS, R850R, R1100R

Engine Code Family:

M257 (Boxer Twin)

👋 Introduction

Target Audience:

Owners of BMW R1100 series motorcycles seeking to perform maintenance, repairs, and diagnostics themselves, or to better understand their vehicle's systems.

Value Proposition:

Provides authoritative and detailed technical guidance, reducing reliance on dealership services and enabling cost-effective maintenance and repairs. Essential for maintaining the longevity and performance of these premium motorcycles.

Manual Utility:

Covers the complete tear down and rebuild, ensuring users have the necessary information for any repair task.

Part Ordering Assistance:

Facilitates accurate part identification, crucial when ordering replacement components.

📋 Manual Details

Vehicle Models Covered:

BMW R1100RT, R1100RS, R850GS, R1100GS, R850R, R1100R

Estimated Page Count:

Approx. 500-800 pages (typical for comprehensive service manuals of this era)

Manual Type:

Service and Repair Manual

Language:

English

Format:

Digital (likely PDF)

📖 Manual Coverage

Engine:

Comprehensive coverage including disassembly, assembly, tuning, diagnostics, and component specifications for the Boxer twin engine (oil-cooled).

Fuel System:

Bosch Motronic fuel injection system, throttle body service, sensor diagnostics, fuel pump, injectors.

Ignition System:

Twin ignition system (spark plugs per cylinder), coil packs, ECU control, timing.

Transmission And Drivetrain:

Clutch operation (dry single-plate or wet multi-plate depending on model), gearbox overhaul, shaft drive maintenance, final drive unit.

Suspension:

Front Telelever suspension system (R1100RT/RS/R), Paralever rear suspension, fork seal replacement, shock absorber adjustments and replacement.

Brakes:

BMW Integral ABS (front brake lever actuates front and rear brakes, rear brake pedal actuates rear brake), ABS modulator service, brake fluid replacement, pad and disc inspection/replacement.

Electrical System:

Wiring diagrams, component testing, battery maintenance, charging system (alternator), starter motor, lighting, instrumentation, CAN bus interfaces (if applicable).

Chassis And Bodywork:

Frame inspection, fairing removal and installation, seat mounting, luggage systems (RT models), fuel tank maintenance.

Routine Maintenance:

Oil changes, filter replacement, spark plug replacement, air filter cleaning/replacement, valve clearance adjustment, brake fluid flush, coolant check/replacement (if liquid-cooled variants exist, though these are primarily oil-cooled), drive shaft lubrication.

Troubleshooting:

Diagnostic charts for common issues, symptom-based troubleshooting guides for engine, electrical, and mechanical systems.

Repair And Overhaul:

Step-by-step instructions for major component repairs, including engine rebuild, transmission overhaul, suspension component replacement, electrical system repairs.

Technical Specifications Data:

Torque values for critical fasteners, engine clearances, diagnostic parameters, fluid capacities, electrical specifications.

Depth Of Coverage:

Comprehensive, suitable for both DIY enthusiasts and professional mechanics. Covers from basic maintenance to complete engine and transmission rebuilds.

📊 Manual Specifications

File Type:

PDF

Searchability:

Likely text-searchable PDF, allowing quick access to specific information.

Image Resolution:

Typically high-resolution images and diagrams suitable for printing.

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Four-stroke, air/oil-cooled Boxer twin-cylinder engine

Displacement:

848 cc (R850) / 1085 cc (R1100)

Bore X Stroke:

R850: 87.5 mm x 69 mm / R1100: 99 mm x 70.5 mm

Compression Ratio:

R850: 10.0:1 / R1100: 10.7:1 (typical, may vary slightly by sub-model)

Horsepower:

R850: Approx. 70-75 HP / R1100: Approx. 80-90 HP (depending on specific model and tuning)

Torque:

R850: Approx. 55-60 lb-ft / R1100: Approx. 70-75 lb-ft (depending on specific model)

Fuel Delivery:

Electronic fuel injection (Bosch Motronic 2.1 or similar)

Fuel Type:

Unleaded gasoline, minimum 91 octane (RON+MON)/2 (equivalent to 87 AKI in North America)

Ignition Type:

Dual spark plug per cylinder, electronic ignition control

Oil Capacity:

Approx. 4.0 - 4.5 liters (including oil filter)

Oil Type Specification:

SAE 20W-50 or 15W-50 API SG or higher, conforming to BMW specifications (consult manual for exact MB approval or equivalent).

🔧 Transmission

Transmission Type:

5-speed manual gearbox

Optional Transmission:

N/A for this generation

Clutch Type:

R1100 models: Dry, single-plate clutch. R850 models may vary, but typically similar.

Final Drive:

Shaft drive to rear wheel

Gearbox Oil Specification:

SAE 75W-90 GL-5 gear oil

Final Drive Oil Specification:

SAE 75W-90 GL-5 gear oil

📐 Dimensions

Wheelbase:

Varies by model (e.g., R1100RT approx. 1430 mm / 56.3 in)

Dry Weight:

Varies by model (e.g., R1100RT approx. 245 kg / 540 lbs)

Gross Vehicle Weight Rating:

Varies by model, typically around 450-480 kg

Fuel Capacity:

Approx. 25 liters (including reserve)

🛡️ Safety Features

ABS System:

BMW Integral ABS (optional or standard depending on sub-model and market)

Braking System:

Hydraulic dual-disc front brakes, hydraulic single-disc rear brake. Integral ABS system activates both brakes with front lever, rear pedal for rear brake only.

Suspension Features:

Telelever front suspension for improved handling and stability, Paralever rear for precise power delivery.

Lighting:

Halogen headlights, integrated turn signals, brake/tail light.

💡 Technology Features

Instrumentation:

Analog tachometer and speedometer, digital odometer, trip meters, fuel gauge, gear indicator, temperature warning lights, clock.

ABS Integration:

Integral ABS system links front and rear braking for enhanced safety, controllable via both brake levers.

Diagnostic Port:

BMW proprietary diagnostic connector for engine management system and ABS diagnostics.

🔧 Maintenance

Oil Change Interval:

Typically every 10,000 km (6,000 miles) or annually, whichever comes first. Consult manual for exact mileage/time.

Valve Clearance Check:

Typically every 20,000 km (12,000 miles).

Brake Fluid Change:

Every 2 years.

Engine Oil Viscosity:

20W-50 or 15W-50 (API SG or higher)

Gearbox Oil Viscosity:

75W-90 GL-5

Final Drive Oil Viscosity:

75W-90 GL-5

Brake Fluid Type:

DOT 4

Common Wear Items:

Clutch wear (especially on earlier models), fuel pump reliability, alternator output, ABS modulator issues, weeping engine seals.

Common Maintenance Tasks:

Regular valve adjustments, thorough inspection of the Telelever and Paralever pivot points for wear, charging system checks.

📚 Vehicle History

Bmw Motorrad Legacy:

BMW Motorrad has a long history of producing reliable and technologically advanced motorcycles, particularly known for their boxer-twin engines and touring capabilities.

R1100 Series Introduction:

The R1100 series, launched in the mid-1990s, represented a significant technological leap for BMW, introducing the oil-cooled Boxer engine, Telelever front suspension, and the Integral ABS system.

Model Variants:

The R1100 platform was adapted into several distinct models: RT (Touring), RS (Sport-Touring), GS (Adventure), and R (Standard/Naked), each with specific chassis and equipment differences.

Production Period:

Mid-1990s to early 2000s (e.g., 1993-2001 for R1100RT).

🏆 Awards & Recognition

Model Reputation:

The R1100 series models, particularly the RT and GS variants, are renowned for their durability, touring comfort, and robust engineering, earning a strong following among motorcycle enthusiasts.

Reliability Perception:

Generally considered reliable with proper maintenance. Many owners report high mileage achievements.