BSA BANTAM D1 1948

 The BSA Bantam is a 2 strike motor cycle that was produced by the Brinbingum arms company  (BSA) from 1948 (as a 125 cc) until 1971 (as a 175 cc

The engine is a unit construction (engine and gearbox of one piece) single cylinder 2 stroke. The barrel is cast iron while the head is alloy. The gearbox was initially three speeds, later versions went to four, fed through a “wet” clutch. Ignition was of two types: a Lucas battery-powered coil in earlier machines, or a m by Wipac. The magneto was on a composite assembly sitting within the flywheel with its magnet inserts; windings gave power either directly to the lights (with a dry cell for when the engine was stopped) or  into a lead acid battery. The early D1s had “fish tail” styled exhausts but this was replaced with the more conventional cylindrical silencer. High-level exhausts were made for the trials and off-road models, in which the only electrics are the magneto-powered ignition.

Manufacturer	BSA
Production	1948–1971
engine	2-stroke 125 cc (D1) 150 cc (D3) 175 cc (D5 Onwards)
power	4.5 bhp (3.4 kW) (D1) 5.3 bhp (4.0 kW) (D3) 7.4 bhp (5.5 kW) (D5 & D7) 10 bhp (7.5 kW) (D10) 12.6 bhp (9.4 kW) (D14/4 & B175)
transmission	Three speed gearbox (D1-D10) Four speed gearbox (D14/4-B175)
Fuel capacity	1.75 imp gal (8.0 l; 2.10 US gal) (“Teardrop” Tanks) 2 imp gal (9.1 l; 2.4 US gal) (D5 & D7) 1.9 imp gal (8.6 l; 2.3 US gal) (D7 Deluxe onwards)