Market Niche:
Entry-level to mid-range motorcycle market in the mid-1970s, appealing to new riders and those seeking a reliable, economical commuter or light sportbike.
Competitors:
Competed with parallel-twin and single-cylinder offerings from Yamaha (XS400, SR500), Honda (CB400 series), Suzuki (GT380, GS400), and other manufacturers.
Engine Configuration:
Parallel-twin cylinder, air-cooled, a configuration that provided a balance of smoothness and power for its class.
Design Philosophy:
Designed to offer a user-friendly, relatively lightweight, and affordable motorcycle with a focus on practicality and ease of maintenance.
Coverage:
Complete service, repair, and maintenance for the 1974 Kawasaki KZ400 motorcycle.
Page Count:
Approximately 200+ pages (estimated based on typical service manual length for this era).
Type:
Factory Authorized Service/Workshop Manual
Engine:
Full engine overhaul, including disassembly, inspection, reassembly, piston/ring replacement, valve adjustments, timing checks, and lubrication system.
Fuel System:
Carburetor tuning, cleaning, rebuilding (Mikuni VM series typically), fuel tank maintenance, and fuel line routing.
Electrical System:
Ignition system (points, condenser, coils), lighting system, charging system (stator, regulator/rectifier), battery maintenance, and wiring diagrams.
Transmission:
Gearbox inspection, lubrication, clutch operation, and shifting mechanism.
Brakes:
Front and rear brake system maintenance, adjustment, pad/shoe replacement, and hydraulic system bleeding (if applicable).
Suspension:
Front fork overhaul, oil replacement, seal replacement, and rear shock absorber inspection and adjustment.
Frame And Bodywork:
Frame inspection, steering head bearing maintenance, body panel removal/installation, and seat assembly.
Routine Maintenance:
Oil changes, filter replacements, spark plug checks, chain adjustment, tire pressure checks, and lubrication points.
Troubleshooting:
Diagnostic procedures for common starting issues, running problems, electrical faults, and braking issues.
Engine Rebuild:
Detailed steps for engine disassembly, cleaning, inspection of wear limits, and reassembly with torque specifications.
Carburetor Rebuild:
Step-by-step guide for cleaning, inspecting jets, floats, and diaphragms, and reassembling carburetors.
Electrical Diagnosis:
Wiring diagrams with component identification and troubleshooting steps for common electrical failures.
Depth:
Comprehensive; covers everything from basic rider maintenance to full engine and component overhauls and troubleshooting.
Engine Type:
Air-cooled, four-stroke, parallel-twin
Displacement:
398 cc (24.3 cubic inches)
Bore X Stroke:
65.0 mm x 58.8 mm (2.56 in x 2.31 in)
Compression Ratio:
9.5:1 (typical for the era)
Horsepower:
Approximately 34 HP @ 8,000 RPM (claimed, may vary)
Torque:
Approximately 23 lb-ft @ 6,500 RPM (claimed, may vary)
Carburetor Type:
Dual Mikuni VM series carburetors (e.g., VM26SC)
Fuel Delivery:
Gravity feed from fuel tank
Ignition Type:
Battery-coil (points ignition)
Length:
Varies by specific model variant, but typically around 2,100 mm (82.7 inches)
Width:
Varies, typically around 750 mm (29.5 inches)
Height:
Varies, typically around 1,100 mm (43.3 inches)
Dry Weight:
Approximately 170 kg (375 lbs)
Wet Weight:
Approximately 185 kg (408 lbs) (with fluids)
Fuel Capacity:
Approximately 10.0 Liters (2.6 US gallons)
Safety Standards:
Compliance with relevant 1970s safety standards for motorcycles.
Braking System:
Front: Disc brake (single piston caliper on most models) / Rear: Drum brake.
Lighting:
Headlight, taillight, brake light, turn signals (where equipped).
Oil Change Interval:
Every 3,000-5,000 km (1,800-3,000 miles) or 6 months.
Valve Adjustment Interval:
Every 6,000-10,000 km (3,700-6,000 miles) or annually.
Spark Plug Check:
Every 6,000 km (3,700 miles).
Engine Oil Type:
API SE, CCMC G2/G3, SAE 20W-40 or 10W-40 (refer to manual for exact recommendation).
Engine Oil Capacity:
Approximately 2.0 Liters (2.1 US quarts) with filter change.
Fork Oil Type:
DEXRON II ATF or SAE 10W fork oil (refer to manual for specific type and viscosity).
Fork Oil Quantity:
Typically 140-160 cc per fork leg (refer to manual).
Carburetor Wear:
Aging rubber components (e.g., diaphragm, O-rings) in carburetors can lead to fuel leaks or poor performance.
Electrical Connections:
Corrosion or looseness in electrical connectors, especially around the ignition coil and stator, can cause intermittent issues.
Cam Chain Tensioner:
The automatic cam chain tensioner can wear, leading to rattling noises from the engine.
Front Fork Seals:
Common for fork seals to degrade over time, leading to oil leaks.
Kawasaki Legacy:
Kawasaki Heavy Industries, Ltd. has a long history in motorcycle manufacturing, known for its performance-oriented and innovative designs.
Kz400 Development:
The KZ400 was part of Kawasaki's successful 'Z' series of motorcycles, introduced to compete in the growing middleweight segment. It paved the way for later parallel-twin and four-cylinder models.
Production Years:
The KZ400 series was produced from 1974 through the early 1980s, with various iterations (A, B, C, D, G models).
Manufacturing Location:
Primarily Japan.
