Royal Enfield 350 BULLET 1949, Workshop Maintenance Manual

Page: 46 / 102

ROYAL ENFIELD WORKSHOP MANUAL
SECTION G3a
Control Box
Used on Models G, J2, "350 Bullet," "500 Bullet," "500 Twin,"
"Meteor 700," 1950 onwards
MODEL RB107
1. General
In Model RB107 control box, the regulator and
cut-out contacts are positioned, for ease of access,
above their respective armatures. It will be noticed
that some of the internal electrical joints are
resistance brazed.
2. Setting Data
(a) Cut-out
Cut-in voltage ...................... 6.3-6.7 volts
Drop-off voltage .......... .. ..... 4.8-5.3 volts
(b) Regulator
Setting on open circuit relative to ambient
temperature :
10° C. (50° F.) ................. ... ....... ... .... 7.7-8.1 volts
20° C. (68° F.) ................. ... ....... ... .... 7.6-8.0 volts
30° C. (86° F.) ................. ... ....... ... .... 7.5-7.9 volts
40° C (104° F.) ………… ……….. … 7.4-7.8 volts
3. Servicing
Before making any adjustment to the regulator,
ensure that the dynamo and battery are in order.
When a sound battery does not keep in a charged
condition, or if the dynamo output does not fall when
the battery is fully charged, the following procedure
should be adopted :
(a) Checking the wiring between battery and
regulator
Remove the control box from its mountings and
withdraw the cable from terminal "A" (see Fig. 1)
and connect it to the negative terminal of a voltmeter.
Connect the positive terminal of the voltmeter to
an earthing point on the machine. If a voltmeter
reading is given, the circuit from the battery to
terminal "A" is in order.
If there is no voltmeter reading, examine the
wiring between the battery and the control box for
defective cables or loose connections. Re-connect the
cable to terminal "A."
Check that the dynamo terminal "D" is connected
to control box terminal "D"and that the cable is in
good condition. Similarly, check the cable between
terminals "F" at the dynamo and control box.
(b) Checking the electrical setting of the
regulator
The regulator is carefully set during manufacture
and, in general, it should not be necessary to make
further adjustment. If, however, the charging system
is suspected it is important that only a good quality
moving coil voltmeter (0-20 volts) is used to check
the system. The electrical setting of the regulator can
be checked without removing the cover from the
control box.
Withdraw the plug-in connectors a small distance,
so that a voltmeter connection can be made to
terminals "D" and "E."
Connect the negative lead of the voltmeter to
control box terminal "D" and the positive lead to
terminal "E."
Remove the negative terminal from the battery. If
coil ignition is fitted, run a temporary connection
from the negative terminal of the battery to the "SW"
terminal of the coil.
Section G3a Page 1
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