🏷️ Basic Information

Make:

BMW

Model:

R80 GS / R100 GS

Year:

1985

Chassis Code:

247

Engine Code Prefix:

247

👋 Introduction

Category:

Dual-sport motorcycle

Segment:

Adventure touring, off-road capable touring

Competitors 1985:

Honda Transalp (later), Yamaha Tenere, Suzuki DR series, Kawasaki KLR

Engine Type:

Air-cooled boxer twin

Drive System:

Shaft drive

Suspension R100Gs:

Monolever rear suspension (single-sided swingarm)

Suspension R80Gs:

Traditional twin rear shock absorbers

Durability:

Renowned for robustness and long-distance touring capability

Off Road Capability:

Designed with significant off-road prowess for its era

📋 Manual Details

Engine:

Yes

Transmission:

Yes

Chassis:

Yes

Electrical System:

Yes

Suspension:

Yes

Brakes:

Yes

Bodywork:

Yes

Fuel System:

Yes

Exhaust System:

Yes

Wheels And Tires:

Yes

Troubleshooting:

Yes

Estimated Pages:

300+

Type:

Service Repair Workshop Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Full overhaul, cylinder head, pistons, crankshaft, timing, valve train

Engine Management:

Ignition system, fuel injection (K-Jetronic for R100, Bing carburetors for R80), starting system, charging system

Transmission Gearbox:

Disassembly, assembly, gear inspection, shifting mechanism

Drivetrain:

Clutch (single plate dry), driveshaft, universal joints, rear axle, final drive

Frame And Suspension:

Frame inspection and repair, front fork (telescopic), rear swingarm, shock absorbers (Monolever for R100GS, twin shocks for R80GS)

Braking System:

Front and rear brake systems (disc brakes), hydraulic lines, master cylinders, calipers, bleeding procedures

Electrical System:

Wiring diagrams, lighting system, instrumentation, battery, starter motor, alternator, ignition coils, fuses

Fuel And Exhaust:

Fuel tank, fuel pump, fuel lines, carburetor overhaul (R80GS), K-Jetronic fuel injection troubleshooting (R100GS), exhaust system components

Routine Maintenance:

Oil changes, filter replacement, spark plug checks, chain adjustment (if applicable, though these are shaft-driven), valve clearance adjustments, lubrication points

Component Overhaul:

Complete engine rebuild, gearbox rebuild, carburetor servicing, fuel injection system servicing, brake caliper overhaul, suspension component rebuild

Troubleshooting Diagnostics:

Step-by-step diagnostic procedures for common starting, running, and electrical issues, fault finding charts

Torque Specifications:

Detailed torque values for all critical fasteners and components

Wiring Diagrams:

Comprehensive electrical schematics for all systems

Special Tools:

Identification and usage of BMW-specific tools required for certain procedures

Depth:

Comprehensive: Covers everything from basic maintenance to full engine and transmission rebuilds, including advanced diagnostics and electrical system repair.

📊 Manual Specifications

Format:

PDF

Searchability:

Likely text-searchable, enabling quick access to specific information

Print Quality:

Dependent on original source, typically clear and legible for printing

Binding Type:

N/A (Digital PDF)

Paper Type:

N/A (Digital PDF)

⚙️ Engine Specifications

Type:

Four-stroke, air-cooled boxer twin

Bore X Stroke R80:

80.0 mm x 78.0 mm

Bore X Stroke R100:

94.0 mm x 70.5 mm

Displacement R80:

797.5 cc

Displacement R100:

980 cc

Compression Ratio R80:

8.2:1

Compression Ratio R100:

8.5:1

Horsepower R80:

50 hp @ 6500 rpm (approx.)

Horsepower R100:

65 hp @ 7250 rpm (approx.)

Torque R80:

57 Nm @ 5000 rpm (approx.)

Torque R100:

78 Nm @ 6000 rpm (approx.)

R80Gs Carburetor:

2 x Bing 32mm constant-vacuum carburetors

R100Gs Fuel Injection:

Bosch L-Jetronic (K-Jetronic) fuel injection system

Fuel Type:

Unleaded gasoline (91 octane or higher)

System:

Wet sump

System:

Breakerless electronic ignition

🔧 Transmission

Type:

5-speed constant mesh gearbox

Drive:

Shaft drive to rear wheel

Clutch:

Single plate, dry type, hydraulically operated

📐 Dimensions

Length Approx:

2200 mm

Width Approx:

900 mm

Height Approx:

1400 mm

Dry Weight R80:

200 kg (approx.)

Dry Weight R100:

207 kg (approx.)

Wet Weight R80:

215 kg (approx.)

Wet Weight R100:

222 kg (approx.)

Gross Vehicle Weight Rating:

370 kg (approx.)

Fuel Tank Capacity:

20 Liters (incl. 3L reserve)

🛡️ Safety Features

Safety Rating:

N/A (Motorcycle safety standards of the era)

Brakes:

Dual 285mm front discs, single 200mm rear disc (R100GS has dual front discs as standard, R80GS often single front disc)

Suspension Stability:

Paralever (on later R100GS models, not 1985) / Monolever (on 1985 R100GS) and well-engineered conventional suspension contribute to stability.

Frame Strength:

Robust steel tube frame construction

Lighting:

Halogen headlamp, integrated turn signals and taillight

💡 Technology Features

Infotainment System:

Not applicable for this model year.

Driver Assistance Systems:

Not applicable for this model year.

Connectivity Features:

Not applicable for this model year.

🔧 Maintenance

Oil Change Engine:

Every 5,000 - 10,000 km or annually

Oil Change Final Drive:

Every 10,000 - 20,000 km

Valve Clearance Check:

Every 10,000 km

Spark Plug Check:

Every 10,000 km

Engine Oil Type:

SAE 20W-50 or SAE 15W-40 motorcycle-specific oil (API SG or higher)

Engine Oil Capacity:

Approx. 2.5 - 3.0 liters (depending on filter change)

Final Drive Oil Type:

SAE 80W-90 hypoid gear oil (API GL-5)

Final Drive Oil Capacity:

Approx. 0.25 liters

Brake Fluid Type:

DOT 4

Clutch Fluid Type:

DOT 4 (if hydraulic)

Oil Leaks:

Common around cylinder head base gaskets and pushrod tubes.

Clutch Slave Cylinder:

Potential for leaks or failure on hydraulically actuated clutches.

Electrical Connections:

Corrosion or loose connections, especially in the charging system and lighting.

Fuel Injection R100Gs:

K-Jetronic can be sensitive to air leaks and requires careful tuning. Injector issues can occur.

Monolever Bearing:

Wear in the Monolever pivot bearing (R100GS) can lead to handling issues.

📚 Vehicle History

Bmw Motorrad Legacy:

BMW Motorrad has a long history of producing durable and reliable motorcycles, particularly known for their boxer-twin engines and shaft drive.

R Series Origin:

The R80GS and R100GS are descendants of the original R80G/S, which defined the dual-sport segment in the early 1980s.

Gs Development:

The 'GS' designation stands for 'Gelände/Straße' (Off-road/Street), highlighting the bikes' dual-purpose design. The R100GS introduced the revolutionary Monolever rear suspension system.

Production Years R80Gs:

1980-1987 (G/S), 1987-1990 (GS)

Production Years R100Gs:

1987-1996 (though 1985 is specifically covered by the manual, models from '87 onwards refined the design)

Manufacturing Location:

Berlin, Germany (BMW Motorrad factory)

🏆 Awards & Recognition

Segment Definitive:

The R80G/S and its successors are widely credited with creating and popularizing the modern dual-sport motorcycle category.

Durability Reputation:

Consistently lauded for their long-term durability and ability to endure demanding conditions.