Triumph MAYFLOWER 1951, Instruction Book

Page: 58 / 86

57
ELECTRICAL SYSTEM
A 12 volt earth return (or one wire) lighting and starting set is fitted.
As the frame parts are not insulated, one cable should be disconnected from the
battery terminal before removing any electrical unit, otherwise there is risk of a
serious "short."
IGNITION
See page 10 for the function of the red warning lamp bulb. Although the failure of this
bulb will not affect the ignition, the bulb should be replaced at the earliest opportunity by
one of the same size and type,
i.e., Lucas No. 987, 12 volt, 2.2 watt
(see page 63).
Misfiring, etc.
If misfiring occurs, check that the fault is not due to a defect in the carburettor, fuel
supply, sparking plugs, etc.
Examine the high tension leads. If they are perished or worn through, replace with
7mm. rubber covered ignition cable.
Cleaning and Adjustment of Distributor Contacts
Every 5,000 miles (8,000 km.) wipe the inside and outside of the moulded
distributor cover with a soft dry cloth, paying particular attention to the space
between the terminals. See that the small carbon brush on the inside of the moulding
works freely on its holder.
Examine the contact breaker. The contacts must be free from grease or oil. If they
are burned or blackened clean them with a fine carborundum stone or with very fine
emery cloth. Afterwards wipe away any trace of dirt or metal dust with a cloth
moistened in petrol.
After cleaning check the contact breaker gap. To do this turn the crankshaft with the
starting handle until the contacts are fully opened and insert a 0.0l5" (0.4 mm.)
gauge between the contacts.
If the setting is correct the gauge will be a sliding fit, but if the gap varies
appreciably from the gauge the setting should be adjusted. Slacken the two screws
securing the plate carrying the fixed contact and move the plate until the gap is set
to the thickness of the gauge, tighten the two screws and re-check the setting.