Puch 1934 “S 4” 250 cc split-single two stroke frame & engine # 82079
From 1889 Johann Puch (1862–1914) worked as an agent for Humber and manufacturer of Styria safety bicycles in a small workshop in Graz and in 1890 he founded his first company Johann Puch & Comp., employing 34 workers. By 1895, Puch already employed more than 300 workers producing about 6000 bikes a year.
In 1897 Puch left the company after a dispute with his business partners.
Two years later he founded the Erste Steiermärkische Fahrradfabrik AG ( “First Styrian Bicycle Factory AG”) in Graz. Puch’s company became successful through innovation and quality handicraft, rapidly expanding over time.
Production of engines was started in 1901 and cars followed in 1904.
In 1912 Johann Puch went into retirement and became the company’s honorary president. In that year the company employed about 1,100 workers and produced 16,000 bicycles and over 300 motorcycles and cars annually.
During World War I, Puch became an important vehicle supplier to the Austro-Hungarian Army.
In 1923 the Italian engineer Giovanni Marcellino is said to have been sent by the banks to wind up the Puch factory in Graz.
But instead he settled down to live in the town and designed and then produced a new version of a split-single two stroke engine.
Marcellino’s design had the pistons one behind the other, unlike Garelli’s pistons, which were side-by-side.
The new system allowed better cylinder filling and a longer power stroke.
To avoid flexing of the connecting rod, the small-end bearing of the cooler intake piston was arranged to slide slightly fore-and-aft in the piston.
In 1931 Puch won the German Grand Prix with a supercharged split-single, though in subsequent years they were overshadowed by the split-singles of DKW.
The “S4” was presented for the 1934 model year and its designation refers to “Sport Viergang”.
It was the first Puch with a four speed gearbox.
At the time it was very powerful for a 250 cc two stroke, delivering 10.5 HP; the sophisticated DKW two-fifty Sport with Schnürle system came to 9 HP only.
The S4 was so well- designed it was carried on till 1942 with only detail changes in specification.
A notable feature of this innovative and well-built two stroke is that the clutch is positioned in the rear wheel hub.
This machine is a fine restoration and she goes like a bat out of hell.