The Enya 19 IV featured a "square " 2 stroke design.
bore/stroke 16mm X 16mm and available only in plain bearing;
0.24 HP at 11,750 RPM
The Enya 19-V Model 4005 was introduced in 1970 featured an "over square design.
bore/stroke 16.5mm X 15mm which was available in a twin ball-race model;
0.28 HP at nearly 13,000 RPM with muffler
Click on the Object below to see the starting and running of this fine old engine.