Systems Covered:
Engine, Transmission, Drivetrain, Fuel System, Ignition System, Electrical System, Chassis, Suspension, Brakes, Bodywork, Maintenance, Troubleshooting, Specifications
Estimated Pages:
Approximately 400-600 pages (typical for comprehensive service manuals of this era)
Type:
Service & Repair Manual
Format:
Downloadable Digital Format (PDF)
Engine:
Complete overhaul, top-end and bottom-end rebuilds, cylinder head, pistons, rings, camshafts, valve train, oil pump, crankcase assembly.
Transmission:
4-speed and 5-speed gearboxes (depending on specific model variant), clutch assembly, primary drive, gear inspection, shift linkage.
Drivetrain:
Final drive, drive chain maintenance, rear sprocket, compensator sprocket, clutch cable routing and adjustment.
Fuel System:
Carburetor identification (e.g., Keihin Butterfly, Linkert for some early Shovelheads), disassembly, cleaning, tuning, fuel tanks, petcocks, fuel lines.
Ignition System:
Points ignition, electronic ignition (later models), spark plugs, ignition coils, timing procedures, battery maintenance, charging system.
Electrical System:
Wiring diagrams, lighting, horn, starter motor, alternator/generator, fuses, switches, battery charging system.
Chassis And Suspension:
Frame inspection, front forks (leading link, telescopic), rear shock absorbers, steering head bearings, swingarm bushings.
Brakes:
Drum brakes (front and rear), hydraulic disc brakes (later models), brake caliper service, master cylinder rebuild, brake fluid specifications.
Bodywork:
Fenders, fuel tank mounting, seat installation, handlebars, control levers, basic fairing (if applicable to model).
Steering And Controls:
Handlebar replacement, throttle and clutch cable adjustments and replacement, steering head bearing service and adjustment.
Wheels And Tires:
Wheel bearing inspection and service, spoke tensioning (if applicable to wheel type), tire mounting and balancing.
Maintenance:
Oil changes, filter replacement, spark plug replacement, chain adjustment, brake adjustments, lubrication points, battery tender connection.
Troubleshooting:
Diagnostic charts for common starting, running, and electrical issues. Symptom-based troubleshooting guides.
Repair And Rebuild:
Step-by-step instructions for major component overhauls and component-level repairs.
Adjustments:
Carburetor tuning, ignition timing, clutch and brake lever adjustments, suspension preload.
Wiring Diagrams:
Detailed, factory-accurate wiring diagrams for all electrical components, facilitating troubleshooting and repair of the electrical system.
Engine Timings:
Detailed procedures for setting ignition timing using points and condenser or electronic ignition systems, crucial for engine performance and longevity.
Depth:
Comprehensive: Covers routine maintenance, diagnostic procedures, component overhaul, and complete engine/transmission rebuilds. Suitable for both experienced DIY mechanics and professional technicians.
Torque Specifications:
Includes specific torque values for all critical fasteners throughout the motorcycle, essential for proper assembly and preventing component failure.
Diagnostic Charts:
Systematic troubleshooting tables that correlate symptoms to potential causes and corrective actions for engine, electrical, and chassis issues.
Engine Type:
Air-cooled, 45-degree V-twin, OHV (Overhead Valve)
Displacement Options:
Primarily 74 cu in (1200cc) and 80 cu in (1340cc) for FL and FX models respectively. Sportster models of this era had smaller displacements but shared the 'Shovelhead' top end design, though distinct engines.
Bore X Stroke 74Ci:
3.4375 in x 4.25 in (87.31 mm x 107.95 mm)
Bore X Stroke 80Ci:
3.50 in x 4.25 in (88.9 mm x 107.95 mm)
Valve Train Design:
OHV with pushrods operating rocker arms in the cylinder heads. Pushrod tubes contain engine oil for lubrication.
Horsepower Est 74Ci:
Approximately 60-65 HP (at the crankshaft, figures vary)
Torque Est 74Ci:
Approximately 70-75 lb-ft (at the crankshaft, figures vary)
Carburetor Options:
Keihin Butterfly (e.g., PD, PE series), sometimes Linkert (earlier transition models), S&S Super E/G (as common aftermarket upgrades).
Fuel Type:
Unleaded gasoline, Octane rating typically 87-91 (depending on compression ratio and specific recommendations).
Oil Capacity:
Approximately 3 quarts (2.8 Liters) for the crankcase and primary drive.
Oil Type:
Harley-Davidson 20W-50 or equivalent motorcycle-specific oil. Conventional mineral oil is standard for this era. Some recommend synthetic blends but must be compatible with wet clutches.
Transmission Type:
4-speed constant mesh manual transmission (early 1970s) or 4-speed Cruise Drive (later iterations, though the manual specifically states '1970' which implies 4-speed exclusively).
Optional Transmission:
5-speed transmission became available later in the Shovelhead production run, but unlikely for 1970 models unless modified.
Clutch Type:
Dry, multi-plate clutch, operated by cable.
Primary Drive:
Primary drive to transmission via a duplex chain, housed in a primary chaincase, typically containing engine oil for lubrication and cooling of clutch components.
Transmission Oil Type:
Typically Harley-Davidson Transmission Fluid or SAE 80W-90 gear oil. Check manual for specific recommendations.
Oil Change Interval:
Every 2,000-3,000 miles (3,200-4,800 km) or annually, whichever comes first. Shorter intervals may be recommended for heavy use or older engines.
Chain Adjustment Interval:
Check and adjust every 1,000 miles (1,600 km) or as needed based on slack.
Spark Plug Replacement:
Every 10,000-15,000 miles (16,000-24,000 km), or as indicated by fouling.
Engine Oil Spec:
Harley-Davidson 20W-50, HD-1 (or equivalent API SG/SH rating or higher for conventional, check manual for specific approvals).
Brake Fluid Spec:
DOT 3 or DOT 4 hydraulic brake fluid for disc brake systems (if equipped). Check manual for specific type.
Primary Chain Case Oil Spec:
Shares engine oil. Therefore, the same 20W-50 motorcycle oil is typically used.
Common Problems:
Oil leaks (especially from base gaskets and pushrod tubes), transmission shifting issues, kickstarter mechanism wear, weak charging systems (generator vs. alternator), carburetor tuning difficulties, vibration damping characteristics.
Wear And Tear:
Valve guide wear, crankpin wear, main bearing wear, and worn shifter forks are common in higher mileage engines.
Heritage:
Harley-Davidson, founded in 1903, is an iconic American motorcycle manufacturer renowned for its V-twin engines and distinctive styling.
Shovelhead Introduction:
The Shovelhead engine, introduced in 1966, replaced the Panhead engine. It featured a distinctive aluminum alloy cylinder head with rocker boxes resembling a shovel's head, hence the nickname.
1970 Model Year Significance:
The 1970 model year saw continued refinement of the Shovelhead engine and chassis, offering various models like the FL Electra Glide (touring) and FX Super Glide (custom styling).
Frame Differences:
Distinction between FL (constant swingarm) and FX (Sturgis-style frame with shorter wheelbase and different rake) chassis is detailed.
Shovelhead Production Period:
1966-1984