To rub dry and caked mud from the frame, tank and mudguards means that the
enamel on these parts will be subjected to an abrasive action which will quickly
destroy the polish. Soak the mud first, and then float it off with copious supplies of
clean water supplied either with a hose or a sponge. If a hose is used, take care not to
direct the stream of water directly on to the hub bearings, magneto and carburetter.
When all dirt is removed, dry and polish off with a clean duster.
The engine and gearbox are best cleaned with a brush and paraffin, and then
dried off with a clean rag.
ENGINE
Lubrication
Lubrication for the engine is provided by oil dissolved in the petrol to provide a
moisture commonly called “petroil”. The filler cap on top of the petrol tank will be
found to incorporate a tubular extension which projects into the tank. This serves as
a measure for lubricating oil and is used for preparing the correct mixture of petrol
and oil required. The correct proportion of oil to petrol is given on page 18, and the
grades of oil recommended should be used as lighter grades may prove unsuitable.
For correct running of the engine and also for adequate lubrication, it is essential
that the oil should be completely dissolved in the petrol, and it is, therefore,
preferable to mix the two in a separate container before pouring into the tank. If this
is not possible, however, as for instance, when obtaining petrol from a wayside pump,
the oil should be put into the petrol after filling up with the latter and the machine
should be shaken thoroughly to ensure correct mixing of the two liquids. If this is not
done, there is a risk of liquid oil undiluted with petrol reaching the carburetter and
clogging the fuel supply system. As the only lubrication for the engine is by means
of fuel drawn in through the carburetter the machine must not be coasted downhill for
long periods with the throttle shut as the engine may suffer seizure through lack of
lubrication.
Ignition Timing
The ignition timing is accurately set within very close limits and there is no manual
adjustment for the rider as this has been found quite unnecessary in practice.
The
contact breaker cam (A) Fig. 2, is keyed on to an extension of the mainshaft, and its
position with reference to the piston position is therefore constant.
Any variation in timing can only be secured by moving the contact breaker
housing (B)
Fig. 2, or the rocker arm (C). The former can be rotated through a very
small angle by releasing the screws (D), not forgetting to retighten them after the
adjustment has been made. It is emphasised that this is a works adjustment rather
than one which the private owner is ever likely to carry out.
In order to obtain correct timing and proper functioning of the contact breaker,
the points must be set when in the fully open position to the correct gap, and this
point should be checked periodically as recommended on page 28. To do this, turn
the engine until the points are fully open and insert a feeler gauge between them. The
correct gap in this position should be .015 in. (.38 mm.) and if this is found to be
wrong release screw (E) about one turn with a screwdriver and move the adjusting
plate up or down until the correct gap of .015 in. has been restored, finally
retightening screw (E).
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