Morning Yoshimasa
Been trying to find anything that details the 1927 600EW power output. This machine is I have to say a bit of an enigma! There are details of just about everything except the horse power. (The 1928 unit is equally as ambiguous.)
The 1927 350EW also throws further confusion, the sales sheet states 3.48hp whilst the specification write up states in excess of 10 hp?
The best I can come up with is the 1929 F.29 (600cc) which from what I can see is fundamentally the same engine unit as the 1927 600cc EW, the Douglas sales sheet for this advertise it as 5.9hp
Hope this is of some help
Steve