Category:
Classic American V-Twin Motorcycle Service Manual
Target Audience:
Harley-Davidson enthusiasts, classic motorcycle restorers, and independent repair shops specializing in vintage motorcycles.
Value Proposition:
Provides essential technical knowledge for maintaining, repairing, and restoring a significant piece of Harley-Davidson history, enabling owners to keep their vintage machines running optimally.
Authenticity:
Covers the specific specifications and procedures for the 1968 Shovelhead era, crucial for accurate restoration and repair.
Completeness:
Offers a comprehensive guide, eliminating the need to consult multiple sources for information.
Engine:
Shovelhead V-Twin engine, including top-end (cylinder heads, valves, pistons), bottom-end (crankshaft, connecting rods, bearings), lubrication system, oil pump, oil filter, and cooling.
Fuel System:
Carburetor (likely Linkert or early Keihin), fuel lines, fuel pump, fuel tank, and petcock.
Ignition System:
Battery ignition, points, condenser, coils, spark plugs, and wiring.
Transmission:
4-speed constant mesh gearbox, clutch assembly, shift mechanism, and primary drive system.
Electrical System:
Charging system (generator, regulator), starting system (starter motor, solenoid), lighting system (headlight, taillight, turn signals), instrumentation, and wiring diagrams.
Suspension:
Front fork (likely FL style springer or early hydraulic), rear shock absorbers, and swingarm.
Brakes:
Front and rear braking systems, including brake drums, brake shoes, brake linkages, and master cylinders (if applicable).
Frame And Bodywork:
Frame construction, fenders, fuel tank, seat assembly, fairing (if equipped), saddlebags, and controls.
Wheels And Tires:
Wheel construction, spokes, bearings, tire types, and pressures.
Maintenance:
Routine servicing, lubrication, fluid changes, filter replacement, tune-ups, and component checks.
Troubleshooting:
Diagnostic procedures for common and uncommon issues, symptom-based troubleshooting charts, and fault finding guides.
Repair:
Detailed step-by-step repair instructions for all major components, including disassembly, inspection, repair, and reassembly.
Rebuilds:
Complete engine, transmission, and carburetor rebuild procedures.
Adjustments:
Carburetor adjustment, ignition timing adjustment, clutch adjustment, and brake adjustment.
Wiring Diagrams:
Complete and detailed electrical wiring schematics.
Depth:
Comprehensive, suitable for professional mechanics and experienced DIY enthusiasts. Covers everything from basic maintenance to full engine rebuilds and complex electrical diagnostics.
Engine Type:
Air-cooled, 45-degree V-twin
Displacement:
74 cubic inches (1200cc)
Bore X Stroke:
3.4375 in. x 4.00 in. (87.3 mm x 101.6 mm)
Compression Ratio:
Approximately 8.0:1 (varies by specific model and tuning)
Horsepower Estimate:
Approximately 60-65 HP @ 5200 RPM
Torque Estimate:
Approximately 75-80 ft-lbs @ 3500 RPM
Carburetor Type:
Typically Harley-Davidson Linkert or early Keihin butterfly type
Fuel Type:
Unleaded gasoline, octane rating as specified by Harley-Davidson (typically 87 or higher).
Type:
Dry sump with external oil tank and gear-driven oil pump.
Oil Capacity:
Approximately 3 quarts (2.8 liters), including oil tank.
Oil Filter:
Cartridge type, location typically near the oil tank or engine case.
Type:
4-speed, constant mesh, foot-shifted
Transmission Options:
Not applicable for this model year and configuration.
Clutch Type:
Wet multi-plate, cable-actuated
Primary Drive:
Chain drive (single row, 1" pitch) housed in a primary case.
Transmission Fluid Type:
SAE 50 motorcycle gear oil, or specific Harley-Davidson recommended lubricant.
Safety Standards:
Vintage motorcycle safety standards applicable at the time of manufacture. Modern crash testing methodologies were not applied.
Braking System:
Drum brakes front and rear. Dual leading shoe front brake often an option or standard on some FL models for improved stopping power.
Frame Construction:
Steel tube frame providing structural integrity.
Lighting:
Halogen headlight, taillight, brake light, and often turn signals for visibility.
Oil Change Interval:
Every 2,000 - 3,000 miles or annually, whichever comes first.
Primary Chain Adjust:
Every 5,000 miles
Ignition Timing Check:
Annually or as needed
Spark Plug Replacement:
Every 6,000 - 10,000 miles
Engine Oil:
SAE 20W-50 or SAE 50 motorcycle specific oil. Avoid modern multi-viscosity oils with friction modifiers unless explicitly stated as compatible with older wet clutches.
Transmission Oil:
SAE 50 gear oil or equivalent.
Primary Chain Case Oil:
SAE 50 gear oil or equivalent (shared with transmission in some configurations, check manual).
Brake Fluid:
DOT 3 or DOT 4 hydraulic fluid (if applicable to later models of this generation, typically drum brakes on this era may not use fluid).
Oil Leaks:
Common due to aging seals, gaskets, and case mating surfaces. Regular inspection and gasket replacement are key.
Carburetor Issues:
Linkert carburetors can be finicky; require precise adjustment and cleaning. Early Keihin carburetors can also develop wear.
Ignition System Reliability:
Points and condenser wear can lead to ignition problems; regular inspection and adjustment are necessary.
Charging System Performance:
Generators and regulators can be prone to failure or underperformance, especially at low RPMs.
Transmission Shifting:
Wear in the transmission can lead to stiff shifting or popping out of gear.
Brand Establishment:
Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer with a rich history of innovation and performance.
Electra Glide Introduction:
The Electra Glide lineage began in the 1960s, evolving from the Duo-Glide, introducing the 'batwing' fairing and a more touring-oriented design.
Shovelhead Engine Introduction:
The Shovelhead engine replaced the Panhead in 1966, characterized by its distinctive rocker boxes that resembled shovels.
Manufacturing Location:
Milwaukee, Wisconsin, USA
Significance 1968:
1968 was a pivotal year, marking further refinement of the Shovelhead platform and solidifying the Electra Glide's position as a premier touring motorcycle.
