Electrical Installation
(See also wiring diagram last in this manual).
The dynamo can deliver 70 watts.
A voltage relay (mounted under the saddle) keeps the dynamo voltage constantly on 8 volts, representing the voltage needed to keep a 6 volt batttery fully charged.
When the battery is fully charged, the dynamo does not deliver any current to it but only to ignition, lights and horn. If more current than the dynamo can deliver is used, the battery steps in to help.
If riding is carried out without a battery, the power lead that otherwise is connected to the + side of the battery must be isolated and prevented from connection to the frame. Otherwise the dynamo will short cirquit.
The charge control lamp shows red, when ignition is turned on. If the engine idles, the lamp still shows red, but as soon as the engine goes up in revs, it goes out as a sign on that the dynamo delivers current.
If the charge control lamp continues to glow, the dynamo does not charge and the fault can be found among the following places:
The commutator can be cleaned out when the ground attatched coal holder is removed. At cleaning a piece of cloth moisted with gasoline or a piece of fine sand paper can be used. The engine can run on idle. (Do not forget to reattach the oil lead running up along the dynamo!)
Faults in the dynamo or in the relay are best repaired in an authorized NIMBUS workshop.
Battery
6 volts, 12 ampere-hours. Minus (-) to frame.
Acid level should be 5 mm over the plates. It can be refilled with destilled water, shold the water have evaporated. The acid level should frequently be checked (with monthly intervals but in strong heat more often). The poles of the battery should be greased with vaseline and not common machine grease. When work with the electrical system is carried out, the ground side of the battery should be disconnected.
The ignition is of battery type and fully automatic.
The cirquit breaker is adjusted with a 0.7 mm gap (gauge 7 in the tool kit).
During adjustments the distributor bowl should be hold firmly towards the cam shaft housing and the screw that holds the adjusting plate should be loose.
The breaker points should bear over their entire surface and must be free from oil. The points can be cleaned with a contact file. If none is availabel, use emery cloth.
The ignition coil - The long prong is inserted in the corresponding contact hole in the distributor bowl. The bow shaped clamp is mounted and finally the adjustment plate fastened.
The ignition timing adjustment depends on the breaker point gap (see above) and gasoline quality and is carried out by turning the distributor and distributor bowl. The letters T and S indicates early (high) and late (low) ignition timing. The timing should be such that a faint ignition knacking could be heard when the engine is working hard. To late ignition timing heats the engine in an unneccesary way, gives an increased fuel consumption and less thrust. When using fuel mixtures with a higher octane number than pure gasoline (for example gasoline-alcohol, gasoline-benzol, addition of tetraethyl lead) the ignition MUST be earlier. If an engine is very hot, the engine can continue to fire when turned off (glow ignition) even if the carburator- and ignition adjustments are correct. If the engine does not stop at idling spead, open the throttle fully or put the machine into gear.
Spark plugs has a 14 mm thread. Electrode distance is 0.7 mm. The spark plug should have the correct glowing number, that is, be able to burn oil away without producing melted carbon pearls. The following spark plugs can be used:
Bosch W 175 T 1 - Champion L 10 S - KLG F 70 - Lodged HN
or corresponding plugs. When mounting a spark plug it is important that the spark plug socket does not break the plugs ceramic isolator.
Controls for light and ignition.
The ignitino key has three positions.
In the first 2 positions, the ignition key can be removed.
The left turning handle regulates the light with the following 4 functions:
Lamps:
Head light: Various vendors.
The light adjustment is carried out according to regulations given by local authorities.