FN 1925ca. “M50” 748cc four cylinder overhead inlet valve frame # 839 engine # 1756B
Responding to demands from sidecarists for more power, FN introduces a 748cc, 7hp four – the Type 700 – for 1914. This new engine is a side valve of ‘T’-head layout, with mechanically operated valves and a mechanical oil pump, which drives the three-speed gearbox via a steel, multi-plate clutch. Pedal starting is dispensed with on the Type 700, a kick-start mechanism is added at the right-hand side of the engine. The engine has long stroke configurations with bore x stroke of 52 x 88mm. The Type 700 has not been in production long before the FN works is seized by the invading German Army in the autumn of 1914. The occupying Germans use the FN factory to manufacture ammunition while continuing production of the Type 700, which has a top speed of around 45mph. Soon after the war the production is resumed with a slightly updated 1914 model. In the course of 1922 the T-configuration is changed to overhead inlet valve configuration: that year there are two models available, the standard T-head Model A and the De Luxe Model that has the new overhead inlet engine. A more robust front fork with fixed legs is introduced in 1923. In the autumn of that year the model M50 is brought out: the four gets chain drive and an enclosed flywheel, to name a few new features. More important perhaps for the customer is the design change in the rolling chassis: the Four gets the same modern looks as the new 348cc OHV machine, with shorter frame and graceful petrol tank. 715×115 balloon low pressure tyres are introduced as an option in July 1924 and are standardised for 1925. But the days of the FN four are almost over now: the new and successful 348 cc OHV single M60 is much cheaper and almost as fast. At the end of 1926 FN four production comes to an end after some 780 machines have been produced.
This robust vintage Four is an older restoration that is fitted with Bosch headlight, balloon tyres, “Kifonet Moto” claxon and practical roll-on centre stand.