Introduction
|
Market Position
|
Segment:
|
Entry-level to mid-range sport underbone/moped
|
Target Audience:
|
Commuters, young riders, performance-oriented riders seeking practical and sporty transportation
|
Competitive Analysis
|
Key Competitors:
|
Honda Supra X 125, Suzuki Satria F150, Kawasaki ZX-130 (market dependent)
|
Key Features
|
Performance Focus:
|
One of the more powerful underbones in its class during its production run
|
Design Appeal:
|
Sporty styling, often incorporating aggressive fairings and graphics
|
Practicality:
|
Fuel efficiency, agility for urban environments, relatively low maintenance costs
|
Manual Value
|
Purpose:
|
Essential tool for owners and technicians for proper maintenance, repair, and troubleshooting.
|
Manual Coverage
|
Systems Covered
|
Engine Mechanical:
|
Top end (cylinder head, valves, camshaft), bottom end (crankshaft, connecting rod, pistons), lubrication, cooling, timing
|
Fuel System:
|
Carburetor (for earlier models) / Fuel Injection (for later models), fuel tank, fuel pump, fuel lines, throttle body, injectors
|
Ignition System:
|
CDI unit, ignition coil, spark plug, stator, pickup coil
|
Transmission Drivetrain:
|
Clutch (automatic centrifugal and manual assist), gearbox, final drive (chain and sprocket)
|
Electrical System:
|
Battery, charging system (alternator/stator), starter motor, lighting system (headlight, taillight, turn signals), horn, instrumentation
|
Chassis Frame:
|
Frame structure, swingarm, linkages
|
Suspension:
|
Front telescopic forks, rear monoshock suspension, linkage system
|
Braking System:
|
Front disc brake, rear disc brake (or drum on some variants), master cylinders, calipers, brake lines
|
Wheels Tires:
|
Wheel assembly, tire specifications, bearing maintenance
|
Bodywork Fairings:
|
Panel removal and installation, seat, fuel tank cover, fairings
|
Controls:
|
Handlebars, levers, pedals, cables
|
Procedures Included
|
General Maintenance:
|
Oil changes, filter replacement, chain lubrication and adjustment, spark plug checks, brake pad checks, tire pressure checks
|
Disassembly Reassembly:
|
Complete step-by-step instructions for major components (engine, transmission, suspension, brakes)
|
Troubleshooting:
|
Diagnostic flowcharts and symptom-based guides for common problems
|
Repair Instructions:
|
Detailed procedures for component repair and replacement
|
Overhaul:
|
Engine and transmission rebuild procedures
|
Electrical Diagnostics:
|
Wiring diagrams with explanations for troubleshooting electrical faults
|
Parts Identification:
|
Exploded views with part numbers for ordering
|
Technical Depth
|
Depth:
|
Comprehensive (covers routine maintenance, diagnostics, repair, and complete overhaul)
|
Detail Level:
|
Factory-level detail with precise specifications and procedures
|
Engine Specifications
|
Primary Engine
|
Type:
|
Four-stroke, SOHC, 4-valve, liquid-cooled, single-cylinder
|
Displacement:
|
134 cc
|
Bore X Stroke:
|
Approx. 54.0 mm x 58.7 mm
|
Compression Ratio:
|
Approx. 11.0:1 (varies slightly by year/market)
|
Performance
|
Horsepower:
|
Approx. 11.8 - 12.2 PS @ 8500 rpm (varies by market and tune)
|
Torque:
|
Approx. 10.7 - 10.9 Nm @ 6500 rpm (varies by market and tune)
|
Fuel System
|
Fuel Delivery:
|
Carburetor (e.g., Mikuni VM22 type) or Electronic Fuel Injection (EFI) depending on model variant and year
|
Fuel Type:
|
Unleaded gasoline
|
Cooling System
|
Cooling Method:
|
Liquid-cooled
|
Lubrication
|
Oil Type:
|
API SG or higher, SAE 10W-40 recommended (check manual for specific viscosity)
|
Oil Capacity:
|
Approx. 0.9 - 1.0 Liters (with oil filter change)
|
Maintenance
|
Service Intervals
|
Engine Oil Change:
|
Every 3,000 km or 3 months, whichever comes first. (Refer to manual for specific interval recommendation).
|
Air Filter Cleaning:
|
Every 6,000 km or 6 months. Replace if damaged or excessively dirty.
|
Spark Plug Check Replace:
|
Check every 6,000 km, replace as needed or every 12,000 km. (Use recommended plug, e.g., NGK CR9E).
|
Chain Lubrication Adjustment:
|
Lubricate every 1,000 km, adjust chain slack every 2,000 km. (Refer to manual for precise slack specification, typically 20-30 mm).
|
Brake Pad Inspection:
|
Inspect at every 3,000 km service.
|
Fluid Specifications
|
Coolant Type:
|
Ethylene glycol-based coolant, mix of 50% coolant and 50% distilled water. (Refer to manual for specific Yamaha coolant recommendation).
|
Brake Fluid Type:
|
DOT 3 or DOT 4 brake fluid (check manual for specific type).
|
Known Issues
|
Clutch Wear:
|
Centrifugal clutch may experience wear over time, leading to slipping or inconsistent engagement, especially with aggressive riding.
|
Engine Overheating:
|
Can occur if coolant levels are low or the cooling system is not functioning properly (e.g., clogged radiator, faulty thermostat).
|
Electrical Connections:
|
Corrosion or loose connections in the electrical system can lead to intermittent faults, especially in humid environments.
|
Recommended Parts
|
Oil Filter Part Number:
|
Commonly uses Yamaha part numbers like 5YP-13440-00 or equivalent aftermarket filters.
|
Spark Plug Recommendation:
|
NGK CR9E or similar (check manual for exact spec).
|