1964 BSA Bantam (D7) 174cc
Original Number DRO 121B
The BSA Bantam is a two stroke unit construction motorcycle that was produced by the Birmingham Small Arms Company (BSA) from 1948 (as a 125 cc) until 1971 (as a 175 cc). Exact production figures are unknown, but it was over 250,000 and some estimates place the number closer to half a million.
The D7 Super was introduced for 1959, had a similar 175cc engine to the D5 but had an entirely new swinging arm frame and hydraulically damped forks which incorporated a nacelle mounted headlamp. The D7 continued in production until 1966 with at least 3 different styles of tank and alterations to the Wipac powered electrical system including a change to battery powered external coil ignition.
ENGINE: D7 Super; 174cc, single cylinder, two-stroke, with petroil lubrication.
Cylinder barrel: cast iron;
Cylinder head: cast aluminium alloy.
Standard bore x stroke: 61.5 x 58mm.
BHP: 7.5 @ 5,000 rpm.
IGNITION: Magneto ignition; Wico-Pacy Series 55/Mark 8. Output: Ignition and rectified d.c. for lighting and battery charging.
Contact breaker gap: .0015in.
Spark plug: Champion L-7; gap: .020in.
Timing: 1/16" before top dead centre (TDC