Which Midget are you referring to as Mk1? There is the pre war Midget and then the Mk 2 & Mk3 came out post war. The Atco Villiers is sometimes referred as the Mk1. If this is the engine that you are interested in there is no actual manual for it that I have been able to find. The majority of the settings such as timing, carburettor settings etc are in the Atco instruction books for the models fitted with this engine.
Jack..thanks for helping to clear up the confusion. The Villiers Midget was first produced in 1931 and replaced by the Mk2 and Mk3 in late 1948. The original was then called the Mk1. My example dates from 1933/34 and has the earlier "sunburst" cylinder fins and is fan cooled. The base/ expansion chamber and the throttle governed carb are similar to the Villiers WXII. (The carb on it now is incorrect) Thanks also to Ron Wiley for supplying this information
Hello Alan Many thanks to you! - as always - for filling in the dots about the Midget. Accuracy is important in a world of myths, I guess.
The amazing thing - for me - is that the commercial version had fan cooling! Motorcycle and lawnmower versions were more simple... it seems.
I think I now understand that the 'sunburst' barrel casting preceded the straight fins. It would appear that the 'beehive' fins are unique to the Atco-Villiers.