Sunbeam 1924 Model 4 600cc 1 cyl sv



Sunbeam 1924   4 ¼   HP   599 cc side valve “Model 4”  frame#  16965  engine #  211/ 19676

The Wolverhampton based firm of John Marston Ltd. earned fame for their superb bicycles at the end of the 19th and beginning of the 20th century.  
In 1912 their first motorcycle was presented.  It was equipped with a  2 ¾  hp engine designed by Harry Stevens, one of the talented family of Stevenses later to found their own company not far from Sunbeamland. 
Stevens acted as a consultant to Marstons and designed a  conventional 349 cc side valve single, with two-speed transmission and forward  placed magneto.  
Further development of engine and cycle parts was then taken over by John Greenwood, a highly competent engineer and rider, who came with the firm in 1912 and remained at Sunbeamland for the rest of his working life, designing almost every Sunbeam motorcycle.  
Greenwood ( who had previously designed the Rover3 ½ HP engine) altered the Stevens design in that he moved the magneto to the position behind the cylinder. 
In general motorcycle design and manufacture was carried out according to the standards set for the Sunbeam bicycles: elegance, silence in operation, reliability and impeccable finish were the keywords.  
At the end of 1913 a 3 ½ HP model  ( 85x88mm) was launched, a model that would make the Sunbeam name world famous.
Nickel plating on Sunbeams was kept to a minimum, almost all parts were enameled black.  
The enamel was of outstanding quality, as witnessed by many vintage Sunbeams still having their first finish… The whole machine followed John Marston’s dictum of the best possible quality allied to the best possible specification.  
The “model 4” was  a more powerful version of the  ‘all purpose “  Model 3.  
It was equipped with the 85 x 105.5  mm Model 7 engine.  
The Model 4 profile in the 1924 catalogue mentions:  “ It will appeal to those who require an outfit of considerable horse power  and yet do not wish to include the refinements incorporated in our  4 ¼  h.p. Model 7.”  
This fine Sunbeam has been restored to a high standard and comes complete with acetylene lighting set and bulb horn.