These are the known mechanical and performance specifications for your 2011 Demak Ex 90.
Basic Specs

Engine
Displacement90.00 ccm (5.49 cubic inches)
Type
DetailsSingle cylinder, four-stroke
Max RPM
Compression
Bore/Stroke
Valves/Cylinder
FuelingCarburettor
Ignition
Exhaust
Lubrication
CoolingAir
Chassis
Frame TypeSteel
Rake
Trail
Front SuspensionTelescopic fork
Front Travel
Rear SuspensionDual shocks
Rear Travel
Seat2-person seat
Seat Height
Alt. Seat Height
Total Height1,043 mm (41.1 inches)
Total Length1,855 mm (73.0 inches)
Total Width665 mm (26.2 inches)
Ground Clearance
Wheelbase
Dry Weight90.0 kg (198.4 pounds)
Wet Weight
Wheels & Brakes
Front Tire/Tyre2.25-17
Rear Tire/Tyre2.50-17
Front Brakes
Front Brake Diameter
Rear BrakesExpanding brake (drum brake)
Rear Brake Diameter
Wheels
Comments
Made in Malaysia. Sold in Asia.