1964 BSA Bantam  (D7) 174cc

Manufacture 11.8.64
175cc
Chassis D742492
Engine FD72509
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.

Technical reference
http://bsarestoration.webs.com/technicalreference.htm

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