Manufacturer: Sun Precision
Model: 3.5hp Sun Precision
Year: 1913
Displacement: 499cc - 3.5hp Precision engine
Bore/stroke: 85x88m
Engine type: Sidevalve four-stroke
Cylinders: One
Gearbox: Sturmey Archer 3 speed hub
This example has a Brown and Barlow carburetor, Druid forks, Bosch magneto and foot-controlled clutch, the latter uncommon on this model and probably retro-fitted.
Courtesy Classic Motorcycles Austria

Sun-Precision 498cc