🏷️ Basic Information

Make:

Jawa

Model:

350 (638, 639, 640)

Year:

2004-2005

Production Codes Covered:

638, 639, 640

👋 Introduction

Brand Legacy:

Jawa is a historic Czechoslovakian motorcycle manufacturer renowned for producing robust, reliable, and relatively simple machines, particularly popular in Eastern Europe and developing markets.

Segment Competitors:

In its segment, Jawa 350 models historically competed with other lightweight to mid-weight motorcycles, often focusing on affordability and ease of maintenance rather than high performance.

Design Philosophy:

The Jawa 350 series is characterized by its iconic parallel-twin, two-stroke engine, straightforward construction, and distinctive styling. The 638, 639, and 640 represent evolutionary steps in this long-standing lineage.

Utility For Owners:

This comprehensive service manual is invaluable for owners of the 2004-2005 Jawa 350 models, providing the necessary technical information to perform all maintenance and repair tasks, thereby extending the motorcycle's lifespan and ensuring optimal performance.

📋 Manual Details

Vehicle Models Covered:

Jawa 350 series motorcycles, specifically the 638, 639, and 640 models from 2004-2005 production years.

Estimated Page Count:

Likely 200-400 pages (typical for a comprehensive service manual of this era and type).

Type:

Service and Repair Manual

Language:

English (presumed, standard for international manuals; likely also includes original Czech if a direct translation).

File Format:

PDF

📖 Manual Coverage

Engine System:

Detailed diagnostics, repair procedures, component overhaul (carburetor, ignition, cooling, lubrication), engine assembly/disassembly.

Transmission System:

Gearbox inspection, repair, clutch adjustment and replacement, shift mechanism.

Fuel System:

Carburetor service and tuning (e.g., Jikov), fuel tank maintenance, fuel line inspection.

Electrical System:

Ignition system (points, coil, spark plug), lighting, charging system (alternator/generator, battery), wiring diagrams, troubleshooting electrical faults.

Suspension System:

Front fork (telescopic) overhaul, rear shock absorber inspection and replacement, linkage maintenance.

Brake System:

Front and rear brake inspection, adjustment, shoe/pad replacement, hydraulic systems (if applicable to specific variants).

Cooling System:

Air cooling system principles and maintenance.

Exhaust System:

Muffler and pipe inspection, sealing, and replacement.

Frame And Body:

Chassis inspection, body panel removal/installation, seat, fenders, handlebars.

Routine Maintenance:

Oil changes, spark plug checks, chain adjustment, brake adjustments, lubrication points, air filter cleaning/replacement.

Troubleshooting:

Diagnostic charts for common running issues, electrical problems, starting difficulties.

Component Overhaul:

Complete disassembly, inspection, and reassembly of engine components, gearbox, forks, etc.

Wiring Diagrams:

Detailed electrical schematics for accurate troubleshooting and repair.

Special Tools:

Identification of required special tools for specific repair procedures.

Engine Rebuild:

Detailed procedures for complete engine disassembly, inspection, component replacement (pistons, rings, bearings), and reassembly.

Wheel And Tire:

Wheel bearing inspection and replacement, tire mounting/dismounting, spoke tensioning (for spoked wheels).

Depth:

Comprehensive, covering everything from basic rider maintenance to major engine and drivetrain rebuilds. Suitable for both DIY enthusiasts and professional mechanics.

Diagnostic Charts:

Includes diagnostic flowcharts or tables to help identify the root cause of common problems based on symptoms.

📊 Manual Specifications

File Type:

PDF

Printable:

Yes, the PDF is designed to be printable, allowing users to create physical copies for workshop use.

Binding Type:

Digital (PDF) - No physical binding.

Digital Format Notes:

High-resolution PDF, ensuring clarity of text and diagrams. Compatible with Adobe Reader across Windows, Mac, and Linux.

Software Requirements:

Adobe PDF Reader (or compatible PDF viewer).

Download Speed:

Instant High Speed Download.

Ease Of Use:

Easy to understand and navigate, often featuring clickable table of contents and search functionality within the PDF.

Coverage Scope:

Full version, indicating comprehensive coverage of all service and repair aspects for the specified models.

⚙️ Engine Specifications

Type:

Air-cooled, two-stroke, parallel-twin cylinder

Displacement:

343.5 cc (approx. 350cc class)

Bore X Stroke:

Approximately 58 mm x 65 mm (varies slightly by model variant).

Compression Ratio:

Typically around 6.8:1 to 7.5:1 (varies by specific model and tuning).

Power Output:

Approximately 20-26 hp (15-19 kW) at 5000-5500 rpm (figures vary by exact model and tuning).

Torque Output:

Around 30-35 Nm (22-26 lb-ft) at 4000-4500 rpm (figures vary).

Carburetor Type:

Typically single or dual Jikov carburetors (e.g., 2828 or 2928 models), or potentially Amal variants in some export markets.

Fuel Type:

Unleaded gasoline with two-stroke oil pre-mix (e.g., 1:50 ratio depending on oil specification).

Type:

Contact breaker points ignition system with a 12V coil and distributor (or dual ignition coils on some later variants).

System:

Premix lubrication (oil mixed with fuel).

🔧 Transmission

Type:

4-speed or 5-speed manual gearbox.

Gear Selection:

Typically foot-lever operated, often with a sequential shift pattern.

Clutch Type:

Wet, multi-plate clutch, operated by a cable-actuated lever.

Final Drive:

Chain drive, with adjustable chain tensioner.

📐 Dimensions

Wheelbase:

Approximately 1400-1450 mm (varies slightly by model).

Seat Height:

Approximately 760-800 mm.

Dry Weight:

Approximately 145-160 kg (varies by model and equipment).

Fuel Tank Capacity:

Approximately 16-18 liters.

🛡️ Safety Features

Crash Test Data:

No formal crash test data typically available for motorcycles of this era and market segment.

Braking System:

Drum brakes front and rear on many variants; some later models may feature disc front brakes. ABS not typically available.

Lighting:

Halogen headlight, taillight, brake light, turn signals.

💡 Technology Features

Features:

Basic instrumentation: speedometer, tachometer (on some models), odometer, neutral indicator, high-beam indicator. No advanced infotainment systems.

Features:

No electronic driver assistance systems typical of modern motorcycles.

Features:

No connectivity features.

🔧 Maintenance

Oil Change Interval:

Premix lubrication, no separate oil change; monitor oil level in fuel. Gearbox oil change recommended every 5,000-10,000 km.

Spark Plug Check:

Every 2,000-4,000 km, or as needed based on performance.

Chain Adjustment:

Regularly, or every 1,000 km, as chain stretch occurs.

Carburetor Cleaning:

As needed, typically every 5,000-10,000 km, or if performance degrades.

Gearbox Oil Type:

Hypoid gear oil, API GL-4, SAE 80W/90 (check manual for exact specification, typically around 1.5-2 liters capacity).

Two Stroke Oil:

High-quality JASO FD or API TC rated two-stroke engine oil for premixing.

Carburetion:

Jikov carburetors can be prone to gumming if fuel is left stagnant; proper jetting and cleaning are essential for smooth running.

Ignition System:

Contact breaker points can wear and require periodic adjustment or replacement. Weak spark can cause starting and running problems.

Engine Seals:

Crankshaft seals can degrade over time, leading to air leaks and poor engine performance (often indicated by smoking from the crankcase).

Electrical Connections:

Older wiring looms can develop corroded connections, leading to intermittent electrical faults.

📚 Vehicle History

Founding And Legacy:

Jawa was founded in Prague in 1929 by František Janeček. The brand became a symbol of Czechoslovakian engineering and a major motorcycle producer in the Eastern Bloc, known for its innovation and ruggedness.

Jawa 350 Lineage:

The Jawa 350 parallel-twin two-stroke has been in continuous production in various forms since the 1950s. The 638, 639, and 640 series represent an evolution of the original 354/360 designs, incorporating styling and minor mechanical updates over decades.

Manufacturing Location:

Týnec nad Sázavou, Czech Republic.

Production Period Covered:

This manual specifically covers 2004-2005 model years, representing a period of continued production and refinement of the 638/639/640 platform.

🏆 Awards & Recognition

Historical Impact:

While not receiving specific 'awards' in the modern sense, Jawa motorcycles have a long history of widespread adoption and popularity across many countries, testament to their reliability and utility.

Owner Satisfaction:

Owners often praise the simplicity, robustness, and distinctive character of Jawa motorcycles, although they acknowledge the need for regular maintenance common to two-stroke engines of that era.