Positioning:
The Yamaha Jog CY50 was a popular entry-level scooter, known for its reliability and ease of use. This manual targets owners and independent repair shops seeking to maintain and repair these models.
Competitors:
Competed with other 50cc scooters from brands like Honda (e.g., Dio, Tact), Suzuki (e.g., Address), and Kymco.
Manual Value:
Provides in-depth, manufacturer-specific information crucial for accurate diagnosis and repair, saving time and money compared to generic guides or trial-and-error methods.
Engine Mechanical:
Engine assembly/disassembly, cylinder, piston, crankshaft, connecting rod, lubrication system, cooling system (air-cooled), valve clearance adjustment (if applicable), timing components.
Fuel System:
Carburetor disassembly, cleaning, adjustment, fuel lines, fuel filter, fuel tank maintenance.
Ignition System:
CDI unit, spark plug, ignition coil, wiring, troubleshooting.
Transmission Drivetrain:
Automatic Transmission (CVT), drive belt inspection/replacement, clutch assembly, variator, torque converter, final drive gears, lubrication.
Brakes:
Front and rear brake system (likely drum or disc), brake pad/shoe replacement, brake fluid replacement, bleeding, caliper/drum inspection.
Suspension Steering:
Front fork assembly, rear shock absorber, steering system components, wheel bearings, alignment checks.
Electrical System:
Wiring diagrams, battery maintenance, lighting system (headlight, taillight, turn signals), horn, starter motor, charging system (stator, regulator/rectifier), fuses.
Bodywork Chassis:
Frame inspection, body panel removal/installation, seat, footboard, storage compartment, fairings.
Routine Maintenance:
Oil changes, air filter cleaning/replacement, spark plug replacement, drive belt inspection, brake adjustments, tire pressure checks, lubrication points.
Troubleshooting:
Diagnostic charts for common problems, electrical faults, engine performance issues, starting problems.
Major Repairs:
Engine overhaul, transmission rebuild, carburetor tuning, suspension component replacement, electrical system repairs.
Special Tools:
Identification and use of specific Yamaha or aftermarket tools required for certain procedures.
Depth:
Comprehensive; covers everything from basic fluid changes to full engine and transmission overhauls.
Engine Type:
2-stroke, single-cylinder
Displacement:
49cc (often quoted as 50cc)
Cooling System:
Forced air-cooled
Bore X Stroke:
Typically around 39.0 mm x 41.4 mm (specifics may vary slightly by sub-model/year)
Compression Ratio:
Typically around 7.0 - 7.2:1
Horsepower:
Approx. 4.0 - 4.5 HP @ 6500-7000 RPM (varies by market regulations and specific tune)
Torque:
Approx. 4.0 - 4.5 Nm @ 6000-6500 RPM (varies by market)
Carburetor Model:
Likely a Mikuni VM12 or similar 12mm carburetor (specific model number will be in the manual)
Fuel Type:
Unleaded gasoline (typically 91 octane or higher)
Oil Mixture Ratio:
Automatic oil injection (pre-mix typically not required unless modified or during break-in of new parts)
Transmission Type:
Automatic Continuously Variable Transmission (CVT)
Drive Belt:
V-belt drive system with centrifugal clutch and variator.
Gear Ratios:
Continuously variable, specific ratios determined by variator and clutch operation.
Transmission Fluid:
Lubrication for the final drive gears. Typically SAE 80 or SAE 85W-90 hypoid gear oil. Manual will specify exact type and quantity.
Length:
Approx. 1650-1700 mm (specifics vary by sub-model)
Width:
Approx. 630-660 mm (specifics vary by sub-model)
Height:
Approx. 1000-1050 mm (specifics vary by sub-model)
Dry Weight:
Approx. 60-65 kg (specifics vary by sub-model)
Curb Weight:
Approx. 65-70 kg (including fluids and battery)
Storage:
Under-seat storage compartment (capacitive sufficient for a helmet or groceries, depending on design).
Safety Standards:
Compliant with relevant regional safety and emissions standards for mopeds/scooters.
Braking System:
Combination of front and rear brakes (likely drum brakes on both ends for earlier models, potential for front disc on later variants). Manual will detail proper adjustment and maintenance.
Lighting:
Headlight, taillight, brake light, turn signals for visibility and signaling intent.
Frame Construction:
Steel frame providing structural integrity.
Engine Oil Change:
Every 3,000 - 5,000 km or annually. Manual will specify exact interval and oil type.
Air Filter Cleaning:
Every 1,000 - 2,000 km or as needed based on operating conditions. Replacement every 6,000 - 10,000 km.
Spark Plug Replacement:
Every 3,000 - 6,000 km or annually. Manual will specify recommended plug type (e.g., NGK CR7E).
Drive Belt Inspection:
Every 3,000 - 5,000 km. Replacement typically recommended between 10,000 - 20,000 km or when wear is evident.
Engine Oil Type:
Yamaha recommends specific 2-stroke oil for the oil injection system, and SAE 80 or 85W-90 gear oil for the final drive. Manual will list exact Yamaha part numbers or specifications.
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid, depending on specification. Manual will confirm.
Common Problems:
Carburetor gumming from infrequent use, worn drive belts, weak starter motors, electrical connection corrosion, and cooling fins becoming clogged with debris.
Performance Degradation:
Loss of power can be attributed to clogged air filters, fouled spark plugs, worn variator rollers, or carburetor issues.
Yamaha Legacy:
Yamaha has a long history of producing reliable and innovative motorcycles and scooters, with the Jog line being a significant part of their urban mobility offerings.
Jog Series:
The Jog series has seen numerous iterations and engine displacements since its inception. The CY50 represents a specific generation of the 50cc model known for its user-friendly design.
Manufacturing Location:
Likely manufactured in Japan or Southeast Asia (e.g., Indonesia, Taiwan) depending on the specific market and year.
