These are the known mechanical and performance specifications for your 2009 Yamaha Neos 4S.
Basic Specs

Engine
Displacement49.40 ccm (3.01 cubic inches)
Type
DetailsSingle cylinder, four-stroke
Max RPM
Compression12.0:1
Bore/Stroke38.0 x 43.6 mm (1.5 x 1.7 inches)
Valves/Cylinder
FuelingInjection
IgnitionTCI
Exhaust
LubricationWet sump
CoolingLiquid
Performance
Horespower3.08 HP (2.2 kW)
Torque3.15 Nm (0.3 kgf-m or 2.3 ft.lbs)
Top Speed
Fuel Economy & Polution
Fuel Consumption
Fuel Capacity5.40 litres (1.43 gallons)
Emissions
Chassis
Frame Type
Rake
Trail
Front SuspensionTelescopic fork
Front Travel
Rear SuspensionUnit swing
Rear Travel
Seat
Seat Height790 mm (31.1 inches) If adjustable, lowest setting.
Alt. Seat Height
Total Height
Total Length1,840 mm (72.4 inches)
Total Width
Ground Clearance
Wheelbase1,275 mm (50.2 inches)
Dry Weight
Wet Weight95.0 kg (209.4 pounds)
Wheels & Brakes
Front Tire/Tyre120/70-12
Rear Tire/Tyre130/70-12
Front BrakesSingle disc
Front Brake Diameter190 mm (7.5 inches)
Rear BrakesExpanding brake (drum brake)
Rear Brake Diameter110 mm (4.3 inches)
Wheels
Comments
Also called Neo´s 4 Stroke