Segment:
125cc Lightweight Sportbike / Naked Bike
Target Audience:
Enthusiast riders, mechanics, owners seeking to maintain and repair their Cagiva Planet
Key Competitors:
Aprilia RS 125, Yamaha TZR 125, Honda NSR 125, Suzuki RG 125, Gilera SP 01
Performance Orientation:
Designed for sporty performance, handling, and rider engagement, leveraging a potent 125cc 2-stroke engine.
Styling:
Often featured aggressive, race-inspired styling characteristic of Cagiva's performance heritage.
Engine Mechanical:
Disassembly, inspection, assembly, tuning, lubrication, cooling system, valve clearance (if applicable for 2-stroke variants or exhaust valves)
Fuel System:
Carburetor (Dell'Orto PHBH or similar), fuel pump, fuel lines, fuel tank, oil injection system
Ignition System:
CDI ignition, spark plug, ignition timing, stator, coil
Exhaust System:
Expansion chamber, muffler, mounting
Transmission Drivetrain:
Clutch operation, gearbox internals, gear selection, final drive (chain and sprockets)
Cooling System:
Radiator, fan, coolant flow, coolant type
Chassis Frame:
Frame inspection, headstock bearings, swingarm bearings
Suspension Front:
Telescopic forks (Marzocchi, Paioli, or similar), oil levels, seal replacement, spring rates
Suspension Rear:
Monoshock or twin shock absorber, linkage system (if applicable), damping adjustment, spring preload
Brakes Front:
Disc brake system, caliper, master cylinder, brake pads, brake fluid type and bleeding procedure, rotor specifications
Brakes Rear:
Disc brake system, caliper, master cylinder, brake pads, brake fluid type and bleeding procedure, rotor specifications
Wheels Tires:
Wheel bearings, rim specifications, tire pressure, tire sizes
Electrical System:
Wiring diagrams, battery, charging system (stator/regulator/rectifier), lighting (headlight, taillight, indicators), horn, starter motor (if applicable), fuses
Bodywork Fairings:
Fairing removal and installation, seating, plastics
Preventative Maintenance:
Oil changes, filter replacement, chain adjustment, spark plug inspection, brake pad checks, coolant checks
Troubleshooting:
Diagnostic flowcharts for common performance issues, starting problems, electrical faults
Engine Overhaul:
Piston replacement, cylinder boring, crankshaft inspection and rebuilding, reed valve service
Suspension Service:
Fork seal replacement, rear shock rebuild/replacement, linkage maintenance
Brake System Overhaul:
Caliper rebuild, master cylinder replacement, brake line bleeding
Electrical Component Replacement:
Stator, regulator/rectifier, CDI unit, switches
Carburetor Tuning Rebuild:
Jetting recommendations, float height adjustment, cleaning procedures
Wheel Bearing Replacement:
Hub maintenance, wheel balancing
Depth:
Comprehensive; covers basic maintenance to complete engine and chassis rebuilds
Diagnostic Information:
Detailed fault finding guides, symptom-based troubleshooting
Torque Specifications:
Includes critical torque values for engine, chassis, and suspension components
Wiring Diagrams:
Full electrical schematics for clear diagnosis and repair
Engine Type:
Liquid-cooled, 2-stroke, single-cylinder
Bore X Stroke:
Typically 56 mm x 50.6 mm (common for this class, check specific manual)
Induction:
Reed valve induction, usually with a single large carburetor (e.g., Dell'Orto PHBH 28-30mm)
Lubrication:
Oil injection system (separate oil tank)
Compression Ratio:
Variable, typically around 12.0:1 to 13.5:1
Horsepower Output:
Around 28-32 HP (depending on market and restrictions)
Torque Output:
Approximately 2.0 - 2.4 kgf-m (14.5 - 17.4 lb-ft)
Carburetor Model:
Dell'Orto PHBH 28/30 AS (typical)
Fuel Type:
Unleaded gasoline (minimum 95 RON recommended)
Engine Oil Type:
2-stroke premix oil, JASO FD or API TC certified
Coolant Type:
Ethylene glycol-based antifreeze/coolant, 50/50 mix with distilled water
Oil Change Frequency:
Every 3,000 - 5,000 km or annually (check manual for specific mileage)
Spark Plug Replacement:
Every 6,000 - 10,000 km, or as per manual recommendations
Air Filter Cleaning:
Every 3,000 km or as needed based on riding conditions
Chain Lubrication:
Every 500 km and after washing/rain, and always before long trips
Brake Fluid Flush:
Every 2 years or as per manual
Transmission Oil:
API GL-4 or GL-5 gear oil, SAE 75W/90 or 80W/90 (verify in manual)
Common Problems:
Wear on 2-stroke engine components (piston, rings, cylinder) due to high revs, carburetor tuning sensitivity, potential electrical connector issues, aging rubber components.
Reliability Notes:
As with most 125cc 2-strokes, requires diligent maintenance and proper usage to ensure longevity.
