Information Pages for the Restoration of the Zündapp KS 600.


Editor:  ERSATZTEIL    DIENST       Hans-Peter HOMMES       41363 Jüchen Kamphausen 156 C/2

Monthly available on our website.  



the 6 volt generator




© 2013 h-p hommes




The 6 Volt Generator.

The ignition system is powered by a Noris or Bosch magneto and does not need any battery power.
The 6 volt generator is only necessary for the lighting system. The sidecar light and the rear light have enough light intensity.
However, many feel the light from the headlamp to be too weak.

With my first bike I felt the light of my headlamp to be too weak. During a trip to Norway through several unlit tunnels I realized that my friend had a much brighter and more intense light than me.

Why was that? There are several factors that optimize a good light

The generator provides a continuous output of 50 watt.


Have the built-in light bulbs the listed wattage or are they bulbs with more consumption?

Has the bulb of the headlamp 25 or 35 watt?

The one of the rear light 3,5 or 10 watt?

If so the generator comes quickly up to its limit.

It may also be noted that the lighting starts being supplied from the generator only from a revolution speed of approx. 1200 to 1500 revolutions of the engine. Up to this speed the battery takes over the power supply.   

E.g. is the bulb of the main headlight too large, it gives a better light for a short time.

In the long run, however, the power of the generator is not sufficient to meet the power consumption and after a short time is the capacity of the battery is exhausted too.

The light is getting weaker and weaker.

The power consumption should not be no higher than the power of the generator.


What can the battery deliver?

6 volt and 8 ampere give a rating of 48 watt for one hour. Using the wrong bulbs we get a consumption of 51 watt.

So the battery is quickly empty.  

When we continue at high speed the mathematical result is a deficit because now the battery needs charging current  in addition. 

To make it short the light is getting more and more yellow and weak.

But this is only factor that can create or cause bad light.


The generator and the governor.

At what speeds provides the generator enough electricity to power the light system?

When does the governor switch the automatic cutout with decreasing speed?

If it switches too late, then the battery will discharge through the generator.

How high is the voltage at which the governor limits the electricity?
Most of the electronic governors
order no. 3170 have no setting options to adjust the amount of charging current to the existing generator.

 When the clearance between the armature and the pole shoe differs from the standard, the governor must be adjusted accordingly.

This can only be accomplished with individually adjustable governor just as we offer it.


Another problem is the overloading of the battery.

This is due to the use of electromechanical regulators and their poor voltage regulation until the 1970s.

The original F-regulator of our Zündapp KS 600 is such a copy.

When loading the entire lead sulfate is converted back into lead and lead dioxide.

In the case of over-voltage the charging current flows on. At the same time the lead of the grid is attacked.

So do not simply install an electronic regulator and hope that it will have the correct charging voltage. You have to set the exact charging voltage for each generator either on a test bench or on the bike.

Set value for the charging voltage

 Nickel Cadmium

7,8 Volt
7,2 Volt

The armature of the generator with ignition cam order no. 3402-3.
Some armatures are milled in a too small diameter. so that the current flow is disturbed. The outer diameter of the armatures is not always the same so that often a larger clearance is formed between the armature and the pole shoes which also influences the intensity of current.
Differences are also found in the type of windings which also effect the function of the governor.

Another cause for the insufficient power of the generator can be wrong or worn out
springs order no. 3406 and coils order no. 3151.
Incorrect or damaged coils give no power supply anymore.
During a complete overhaul the coils order no. 3017 should always be replaced.

Many small errors lead to the result that there is not enough power supply to operate the lighting system. Last but not least a good quality reflector is necessary to produce a bright light cone. After a systematic overhaul of my generator I got a much brighter and constant light in all speed ranges.

It is now fully sufficient to drive the bike a long time in the dark.


When repairing the generator many of us only make sure that light is produced. But this light is not stable and obtains part of the necessary energy already from the battery.

The light is getting weaker. To get the generator under control quite often the reaction to our own disability is something like this: the 6 volt system is too weak, this was always the problem, we need something else, etc….


The 6 volt system works efficiently when it is properly repaired.

Then the headlamp has a good bright light that does not collapse even with lower speed.

We restore the generators for Zündapp KS 600 and KS 750.
We have all necessary parts in our program.
Including armatures with ignition cams, adjustable electronic regulators etc..

We offer:

Spare parts + Accessories + Repair for Engines, Transmissions, etc. of 
Zündapp KS 750 and 600

We offer:

Spare parts + Accessories + Repair
of BMW R75 and Zündapp


H-P Hommes Ersatzteil-Dienst
Ersatzteile + Instandsetzungen
repairing + restoring

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