Introduced at the 1922 Olympia Show, the Model L was supplied with both sidevalve and OHV engines which each had a bore and stroke of 72mm x 85.5mm. The OHV model was the first such machine which BSA produced, and shared the remainder of its specification with the SV model - three-speed gearbox with hand-change, chain final drive, an Amac carburettor, and dummy rim brakes front and rear.
Lubrication was via a mechanical oil pump but the rider could adjust the oil flow using an adjuster mounted on the petrol tank which included a sight glass which enabled observation of the flow rate.
The L model achieved success at the 1923 Scottish Six Day Trial. The BSA 350 team riders were B.L. Bird, J.H. Walker and H.S. Perry.
2¾ H.P. Model.
72x85.5 mm. (349 c.c.); single cyl. four-stroke; side valves; mechanical lubrication; B.S.A. carb.; chain-driven mag.; 3-sp. gear; clutch and kick-starter; chain drive; 26x2¼in. tyres. Price £57 15s.
The features of the new B.S.A. 349 c.c. medium-weight model are similar to the sports machine already described, and with the firm's great reputation behind it, it forms a welcome addition to the range.