Segment:
Lightweight sport/street motorcycle
Target Audience:
Enthusiasts and owners seeking detailed maintenance and repair information for their 1990 Cagiva N90.
Contemporaries:
Competed with models from Yamaha (e.g., TZR series), Suzuki (e.g., RG series), Honda (e.g., CBR series), and Aprilia in the 125cc-250cc sportbike segment.
Design Philosophy:
Italian design flair with a focus on sporty performance and handling for its class.
Distinguishing Elements:
Aggressive styling for its era, often featuring vibrant color schemes and performance-oriented components.
Engine Mechanical:
Top-end, bottom-end, cooling, lubrication, valve timing, piston/ring inspection, crankshaft, connecting rods, cylinder head overhaul, gaskets and seals.
Fuel System:
Carburetor overhaul (Dell'Orto PHBH 28 BS), fuel tank, fuel lines, fuel pump (if applicable), fuel filter.
Ignition System:
CDI ignition, spark plugs, ignition coil, stator, wiring, timing adjustment.
Transmission:
Clutch operation (multi-plate wet), gearbox overhaul, shift mechanism, chain drive maintenance, sprocket replacement, lubrication.
Electrical System:
Wiring diagrams, battery, charging system (alternator/stator), lighting (headlight, taillight, indicators), horn, starter motor, instrumentation, fuses.
Braking System:
Front disc brake (hydraulic), rear drum brake, brake fluid, master cylinders, calipers, brake pads/shoes, brake lines.
Suspension:
Front telescopic forks (Marzocchi), rear monoshock absorber, spring rates, damping adjustments, fork seal replacement, linkage maintenance.
Frame And Chassis:
Frame inspection, steering head bearings, wheel bearings, swingarm pivot, exhaust system.
Cooling System:
Air-cooled engine.
Routine Maintenance:
Oil changes, filter replacements, chain adjustments, spark plug checks, brake adjustments, tire pressure checks, lubrication points.
Engine Rebuild:
Complete engine disassembly, inspection, component replacement, reassembly, torque specifications.
Carburetor Tuning:
Jetting, idle speed adjustment, mixture screw settings, float height adjustment.
Electrical Troubleshooting:
Diagnostic charts, common fault identification, wiring repair techniques.
Suspension Overhaul:
Fork seal replacement, oil changes, damper adjustments.
Brake System Repair:
Pad/shoe replacement, caliper/master cylinder rebuild, bleeding procedures.
Wheel And Tire Service:
Tire changes, tube replacement, wheel balancing, spoke tensioning (if applicable).
Depth:
Comprehensive from basic maintenance to full engine and gearbox rebuilds. Includes detailed diagnostic procedures and component-specific repair instructions.
Type:
Two-stroke, single-cylinder, liquid-cooled (typically, though some variants might be air-cooled; manual will confirm specific variant).
Displacement:
Approximately 125cc (confirm via manual for specific N90 variant)
Bore X Stroke:
Specifications provided in manual.
Power Output Hp:
Estimated 20-25 HP (subject to specific tuning and regional variants).
Torque Nm:
Specifications provided in manual.
Carburetor Model:
Dell'Orto PHBH 28 BS
Fuel Type:
Unleaded gasoline with appropriate 2-stroke oil pre-mix ratio (typically 2% or 50:1, as specified by Cagiva).
System:
Premix or separate oil injection system (confirm via manual).
Length:
Specifications provided in manual.
Width:
Specifications provided in manual.
Height:
Specifications provided in manual.
Dry Weight:
Estimated 120-130 kg (confirm via manual).
Wet Weight:
Specifications provided in manual.
Front Tire Size:
Typically 100/80-17 or similar.
Rear Tire Size:
Typically 120/80-17 or similar.
Front Wheel Size:
17 inch
Engine Oil Change:
Every 3,000 km or annually (refer to manual for exact interval).
Spark Plug Check:
Every 3,000-5,000 km.
Chain Lubrication Adjustment:
Every 500-1000 km or after riding in wet conditions.
Engine Oil:
Refer to manual for specific 2-stroke oil type and pre-mix ratio (e.g., Motul 710 2T or equivalent).
Brake Fluid:
DOT 3 or DOT 4 (confirm via manual).
Coolant:
N/A (Air-cooled engine, unless specific variant).
Carburetor Maintenance:
Dell'Orto carbs can be sensitive to dirt and require regular cleaning and adjustment for optimal performance.
Electrical Connections:
Older wiring harnesses may degrade, leading to intermittent electrical issues. Manual provides wiring diagrams for troubleshooting.
Two Stroke Engine Wear:
Two-stroke engines require careful maintenance regarding lubrication and heat management to prevent premature wear of piston and cylinder.
Suspension Seals:
Fork seals can degrade over time; manual provides procedures for replacement.
