Rear Suspension (models D3 and D5)
The two suspension units each comprise a telescopic damper unit and a totally
enclosed coil spring. The hydraulic dampers require no attention whatsoever. They
are sealed during manufacture and if they suffer damage or become ineffective they
must be replaced.
The complete suspension units can be removed from the frame after detaching
the pivot bolts at the top and the retaining nuts at the bottom.
Frame
The frame will not require any attention unless the machine has been involved in an
accident. It should then be inspected very carefully and the wheel alignment
checked. If the frame is damaged or distorted it must be replaced or returned to your
B.S.A. dealer for rectification if feasible.
The rear fork silent-bloc bushes have an extremely long life and the need for
replacement is unlikely.
THE ELECTRICAL SYSTEM
The equipment consists of a permanent magnet alternator which on the basic model
supplies direct lighting. On those machines fitted with battery lighting the alternator
charges a battery via a rectifier. The electrical apparatus (i.e., lights and horn), is
connected to the battery. It is the function of the alternator and rectifier to maintain
the battery in a charged state for all load conditions. This is accomplished by a
system of coil switching, which adjusts the generator output according to the load.
The coil design also ensures regulation of the output over the working speed range.
Battery
Access to the battery is obtained by removing the two nuts and washers under the rear
of the dual seat so that the seat can be lifted and pulled away to the rear. Remove the
two small bolts securing the top strap to gain access to the top of the battery, and by
merely unscrewing the two battery terminals the battery is left free to be lifted out.
About once a month take off the battery lid, remove the filler plugs from each of
the cells and examine the level of the electrolyte. If necessary, add sufficient distilled
water to bring the level of the electrolyte up to the top of the separators. Do not use
tap water and do not use a naked light when examining the conditions of the cells.
The condition of the battery should occasionally be checked by taking
hydrometer readings of the specific gravity of the electrolyte. If distilled water has
been added a reading should not be taken until after the machine has been used, to
ensure that the electrolyte is thoroughly mixed. The specific gravity readings should
be as follows:—
27
