Description:
Essential resource for owners and mechanics of the iconic Harley-Davidson WLA motorcycle, particularly those engaged in restoration or maintaining historical military vehicles.
Value Proposition:
Provides authoritative, factory-level repair and maintenance information that is crucial for preserving the originality and operational integrity of the WLA model, which is highly sought after in vintage motorcycle circles.
Completeness:
Comprehensive coverage encompassing engine, transmission, electrical, and chassis systems, catering to a wide range of repair and maintenance needs.
Historical Context:
Directly relevant to one of Harley-Davidson's most significant models, produced in large numbers for military service during World War II.
Engine:
Complete engine disassembly, inspection, repair, and reassembly. Covers cylinder heads, pistons, connecting rods, crankshaft, camshaft, valve train, timing, lubrication system, cooling system (if applicable), and ignition system.
Transmission:
Service and repair of the gearbox, clutch, and final drive assembly. Includes detailed procedures for gear selection, bearing replacement, and shift mechanism adjustments.
Electrical System:
Wiring diagrams, component testing, troubleshooting for ignition, lighting, charging system (generator/alternator), and accessories.
Chassis And Suspension:
Front fork (leading link or telescopic, depending on specific WLA variant), rear suspension (rigid or sprung seat post), frame inspection and repair, wheel and tire service, braking system (mechanical drum brakes).
Fuel System:
Carburetor servicing (e.g., Linkert M-series), fuel tank maintenance, fuel lines, and fuel petcock.
Brake System:
Front and rear brake shoe inspection, adjustment, and replacement. Drum cleaning and maintenance.
Maintenance:
Routine maintenance checks, lubrication points and schedules, filter replacement, carburetor tuning, ignition timing adjustment, brake adjustments.
Troubleshooting:
Diagnostic procedures for common performance issues, starting problems, electrical faults, and mechanical failures. Includes symptom-based troubleshooting guides.
Repair:
Step-by-step instructions for repairing or replacing all major and minor components of the motorcycle.
Rebuild Refurbish Restore:
Comprehensive guidance for complete engine, transmission, and chassis rebuilds, including parts specifications, tolerances, and assembly sequences.
Depth:
Extensive, covering from basic servicing to complete engine and component overhauls. Detailed diagrams and torque specifications are provided.
Engine Type:
45 cubic inch (737cc) V-twin, OHV (Overhead Valve)
Bore X Stroke:
3.0625 in x 3.25 in (77.79 mm x 82.55 mm)
Compression Ratio:
Approximately 5.0:1 (varied slightly by production year and military spec)
Cylinder Material:
Cast Iron
Cooling System:
Air-cooled
Horsepower Approximate:
Approx. 23-25 HP @ 4800 RPM
Torque Approximate:
Approx. 30-32 ft-lbs @ 3000 RPM
Carburetor:
Linkert M-series (e.g., M-16, M-18, M-21 depending on year and application)
Oil Type:
SAE 50 or SAE 60 motorcycle specific oil (check manual for exact specifications and seasonal recommendations)
Oil Capacity Approximate:
3 US Quarts (approx. 2.8 Liters)
Oil Change:
Refer to manual; typically every 1000-1500 miles or seasonally.
Tune Up:
Regular checks of ignition timing, carburetor settings, and valve lash are critical and may be required more frequently than oil changes.
Brake Adjustment:
Periodic adjustment as per manual due to wear and stretching of cables and brake shoes.
Engine Oil:
SAE 50 or SAE 60 Motorcycle Oil. Consult manual for specific viscosity and additive requirements (e.g., ZDDP content).
Transmission Oil:
Specific heavy gear oil, refer to manual for type and viscosity. Capacity is usually less than 1 US pint.
Primary Chain Case Oil:
Refer to manual; typically shares oil with the transmission or uses specific primary oil.
Fork Oil:
Refer to manual for type and viscosity (often heavier weight fork oil or light motor oil for earlier models).
Carburetor Issues:
Linkert carburetors can be prone to wear, gumming, and difficulty in maintaining a stable idle if not properly serviced and adjusted. Diaphragm issues are common.
Ignition Timing:
Maintaining precise ignition timing is crucial for performance and engine longevity. Points and condenser require regular cleaning and adjustment.
Oil Leaks:
Common in older V-twins due to aging seals and gaskets. Regular inspection and gasket replacement are necessary.
Brake Performance:
Drum brakes offer limited stopping power by modern standards and require frequent adjustment and cleaning of shoes and drums.
Charging System:
Original generators can be unreliable; proper voltage regulation is key. Battery maintenance is essential.
Manufacturer:
Harley-Davidson Motor Company, Milwaukee, Wisconsin, USA.
Development Context:
Developed in response to US Army requirements for a versatile motorcycle for reconnaissance, dispatch, and liaison duties during WWII. Based on the civilian Servi-Car engine and frame but heavily modified for military use.
Key Variants:
WLA (standard military), WL (civilian version), WSP (sidecar version).
Production Years:
1940-1945
Production Volume:
Over 90,000 units produced for the US and Allied forces.
Military Use:
Widely used by the US Army, US Marine Corps, and supplied to Allied nations under Lend-Lease.
