The earliest type had a 362 cc engine with automatic overhead inlet valves and side exhaust valves.
The machine was single geared, had shaft drive and the top speed was about 60 km/hour.
The FN four was an immediate success and found customers all over the world; FN sold its machines in more than 40 countries.
It found many customers in the U.S.A. and made Americans interested in the four cylinder concept: Percy Pierce purchased a 1908 model on one of his trips to Europe and the FN became a point of reference for the first Pierce Four in 1909.
The design was developed to 493 cc and the machine got a proper clutch and gearbox in the years before World War One.
In 1914 the engine was completely redesigned: it grew to 750 cc with mechanically operated inlet valves. Both inlet and exhaust valves were side valves.
The machine had a sturdy clutch and a three speed gearbox. Shortly after the first world war we saw another design change: the side valve inlet system changed to overhead again.
In the autumn of 1923 the model M 50 was marketed: the machine got chain drive and the flywheel was enclosed by the crankcase, to name a few new features.
But the days of the FN four were almost over now: the new and successful 348 cc OHV single M 60 was much cheaper and almost as fast.
At the end of 1926 M50 production came to an end. Only some 780 units were produced during the model`s lifespan.
This older restoration FN Four is in excellent working order.
It was sold new in Switzerland and is fitted with Amac carburettor, 400 x18 Continental tyres and Swiss ED speedometer.
Report by yesterdays.nl