Harley Davidson 1917 “17F” 989 cc IOE V-twin
The first V-twin Harley prototype was displayed at the Chicago Motorcycle Show in February 1907, but it wasn’t until 1909 that the first twins were for sale; officially they were still considered prototypes and only 27 were sold.
The engine had a capacity of 880 cc and had atmospheric intake valves.
The standard colour of these machines was Renault Gray with carmine striping.
The engines were not as good as the company expected so for 1910 no twins were offered and further development work was done.
In 1911 a new engine was presented with 811 cc capacity and IOE configuration.
This proved to be a sound design and it was developed further year after year. In 1912 a bigger, 989 cc engine was an option and in 1913 the 989 cc engine became standard.
In 1915 a three speed countershaft gearbox was fitted and in 1917, the first year of war for the U.S., olive green became the standard colour for all Harley Davidson machines.
The twin could be ordered with magneto ignition (“F”) or battery and coil ignition (“J”).
Changes to the valve gear led to extended valve overlap, resulting in significantly more power.
The output now was 14 HP @ 3,200 rpm. Compression ratio was relatively low at 3.75:1 and the unladen weight was 150 kgs.
This machine is an older restoration and a good runner.
(Source: “Harley Davidson, all the Motorcycles 1903-1983” by Matthias Gerst.)