THE 1928 A.J.S. range is designated by the letter K. There are ten models marketed this year, three of which, viz., K.12, K.10, and K.7 are entirely new productions and were introduced to the general public at the 1927 Olympia Exhibition. These three models are of special interest and are deserving of description in some detail. Model K.12 is the "baby" of the A.J.S. range, while Model K.10 represents the opposite extreme. The first mentioned machine has a 248 c.c. engine installed, and is a perfect miniature in all respects of the 348 c.c. model.
Tyres. Larger size tyres are now fitted. On the passenger models in place of 26 in. by 3.25 in. tyres, tyres measuring 26 in. by 3:5 in. are now provided. These are the largest size tyres used on A.J.S. machines. Next in order of size come covers 26 in. by 3 in. which are fitted to models K.3, K.6, K.7. The remaining models, with the exception of K.5, K.12; are equipped with 26 in. by 3.25 in. tyres. Model K.5 has tyres 26 in. by 2.75 in., while the lightweight model, K.12, has tyres measuring only 25 in. by 3 in.
Lubrication. Mechanical oil pumps with auxiliary hand pumps are now fitted to all models except K.5, where the fitting of a mechanical pump is optional. In the case of the overhead camshaft machines a new lubrication system working on the "dry sump" principle is employed. This system is described elsewhere.
AJS 1928 K7 K10 Overhead Camshaft Models
Source: The Book of the AJS (1927-1928), by W.C. Haycraft. Pitmans.
