Engine Mechanical:
Complete engine overhaul, cylinder head, piston, crankshaft, valve timing, lubrication system, cooling system
Fuel System:
Carburetor(s) (Mikuni/Keihin likely), fuel pump, fuel lines, fuel tank, fuel filter
Ignition System:
CDI unit, ignition coil, spark plug, stator, wiring
Transmission:
CVT (Continuously Variable Transmission) service, variator, clutch, belt, drive/driven pulleys
Chassis Frame:
Frame inspection, alignment, welding points, fairing removal/installation
Suspension Front:
Telescopic fork service, oil seals, springs, damping adjustments, steering head bearings
Suspension Rear:
Swingarm service, rear shock absorber adjustment/replacement, linkage (if applicable)
Braking System Front:
Brake caliper overhaul, master cylinder, brake lines, brake disc, pad replacement, bleeding procedure
Braking System Rear:
Brake caliper overhaul, master cylinder, brake lines, brake disc, pad replacement, bleeding procedure
Electrical System:
Wiring diagrams, battery, starter motor, alternator, lighting (headlight, taillight, indicators), horn, fuses, relays
Cooling System:
Radiator, fan, coolant hoses, thermostat, coolant specifications
Exhaust System:
Muffler, exhaust pipe, gaskets, emissions controls (if applicable)
Routine Maintenance:
Oil changes, filter replacement, spark plug checks, chain adjustment (if applicable), tire pressure checks
Troubleshooting:
Diagnostic charts for common problems, symptom-based solutions
Engine Repair:
Complete engine rebuild procedures, component replacement (pistons, rings, valves, bearings)
Transmission Repair:
CVT belt replacement, clutch inspection, variator maintenance
Brake System Repair:
Brake caliper rebuilding, master cylinder replacement, fluid flushing and bleeding
Electrical Diagnosis:
Fault finding for starting, charging, and lighting systems
Suspension Overhaul:
Fork seal replacement, rear shock mounting and adjustment
Wiring Diagram Interpretation:
Detailed color-coded wiring diagrams for all electrical circuits
Depth Level:
Comprehensive factory-level service and repair
Torque Specifications:
Precise torque values for all fasteners and critical components
Clearances And Tolerances:
Engine component clearances, bearing tolerances, brake pad measurements
Special Tools:
Identification and use of specific Aprilia or aftermarket tools required for repairs
Engine Type:
Single-cylinder, 4-stroke, liquid-cooled
Displacement 250:
244 cc (approximately)
Displacement 300:
263 cc (approximately)
Bore X Stroke 250:
72 mm x 60 mm (typical for this era engine)
Bore X Stroke 300:
74 mm x 60 mm (typical for this era engine)
Compression Ratio:
Approx. 10.5:1 - 11.0:1
Horsepower 250:
Approx. 20-22 HP @ 7500 RPM
Horsepower 300:
Approx. 22-24 HP @ 7500 RPM
Torque 250:
Approx. 20-22 Nm @ 6000 RPM
Torque 300:
Approx. 22-24 Nm @ 6000 RPM
Carburetion:
Single Mikuni BSR40 or similar (specific model dependent)
Fuel Delivery:
Gravity feed with vacuum operated fuel pump
Fuel Type:
Unleaded gasoline, minimum 91 octane (RON+MON)/95 (RON)
Valve Actuation:
SOHC, 4 valves per cylinder
Valve Lash Adjustment:
Shim-under-bucket adjustment
Engine Oil Change:
Every 3,000 - 5,000 km or annually
Oil Filter Replacement:
Every engine oil change
Spark Plug Replacement:
Every 6,000 - 10,000 km
Air Filter Cleaning Replacement:
Every 3,000 - 6,000 km, replacement as needed
Cvt Belt Inspection Replacement:
Inspect every 6,000 km, replace every 12,000 - 20,000 km (depending on wear)
Valve Lash Adjustment:
Every 10,000 - 15,000 km
Engine Oil Type:
SAE 10W-40, API SG or higher, JASO MA (verify specific recommendation)
Engine Oil Capacity:
Approx. 1.3 - 1.5 Liters (with filter change)
Coolant Type:
Ethylene glycol based antifreeze, 50/50 mix with distilled water
Brake Fluid Type:
DOT 4 (verify specific recommendation)
Common Wear Items:
CVT belt, variator rollers, brake pads, suspension seals, starter motor brushes
Carburetor Tuning:
Can be sensitive to altitude and fuel quality, requires periodic cleaning and adjustment
Electrical Connectors:
Corrosion or loose connections can cause intermittent electrical faults
