Powerdynamo brings new ignition & light 
to your vintage motorcycle



Technical Help



Assembly Instructions for System 70 80 499 0XX

Version 15.11.2012

If you can install your stock dynamo/alternator and possess basic mechanical skills, you can install a Powerdynamo!
If you never have worked on your electrical system, better have it done by someone who knows.

Powerdynamo can not monitor the compliance to those instructions, nor the conditions and methods of installation, operation, usage and maintenance of the system. Improper installation may result in damage to property and possibly even bodily injury. Therefore we assume no responsibility for loss, damage or cost which result from, or are in any way related to, incorrect installation, improper operation, or incorrect use and maintenance. We reserve the right to make changes to the product, technical data or assembly and operating instructions without prior notice. 



Please read these instructions fully and carefully before starting work on your motorcycle
Please bear in mind that any modification of the material as well as own repair attempts which have not been agreed with Powerdynamo may result in a loss of warranty. Do not cut off wires. This leads to a loss of reverse polarity protection and often results in damage to electronics. Also, please take note of the information provided on the information page for this system. Check that what you have bought really corresponds to the motorcycle you have. During assembly check carefully that the rotor (flywheel) does not touch the stator coils or anything else, which may happen due to various circumstances and lead to severe damage.
Designated use
This system is designated to replace stock dynamo/alternator in vintage and classic motorcycles. As it is a voltage generating unit only, it will in not change your engine characteristics. In most cases it will supply more electric power and hence enhance roadworthiness and comfort by offering better lighting, better function of side indicators and horn and, compared with the aging stock systems, increased reliability.

The system does not replace your ignition. Ignition must be either a compleately selfsupplying magneto or there has to be a battery in the system. The system has not been tested to work with a third party electonic ignition. it may work with it, but also may not and even may damage it. At any rate the system will charge your battery well.
The charging system is only suitable for use with rechargable 12V (6V systems 6V) lead-acid batteries with  liquide electrolyte or sealed lead-acid batteries, AGM, Gel. It is not suitable for use with nickel-cadmium, nickel-metal-hydride, lithium-ion or any other types of recharchable or non rechargable batteries.

This is a replacement system and not a copy of the stock material. The parts in this system therefore look different and might fit differently (notably ignition coil and regulator) requiring some adaptation by you.

During assembly imperatively start with assy of engine based parts to see that those really fit before you start fitting the external parts. In many cases customers assemble those first and thereby often modify them in breach of warranty which renders them unfit for renewed sale. Replacing old electrical systems is not a matter of taking something from a supermarket shelf as there have been very many types, versions and possibly unknown aftermarket modifications which harbour plenty of room for error.
Our systems are NOT tested for use with third party electronic devices (such as GPS, mobile phones, LED lighting or electronic ignition)and may cause damage to such parts. Possibly existing  electronic tachometers will not work with the new system. Read our information for suitable solutions. Possibly existing safety switches and electronic valve controls are not supported.
If you have no expertise for the installation have it done by an expert or at a specialist's workshop. Improper installation may damage the new system and your motorcycle, possibly even lead to bodily harm.
Before you order a system, please check whether a puller tool  for the new rotor is included in the kit. If not, better order it at the same time. You might want to order light bulbs, fuse, horn, flasher unit etc.
Never use anything other than  the recommended puller tool to pull the new rotor again. Damage to the rotor as a result of use of other  tools or methods is not covered by warranty.
The rotor is sensible to blows (including during transport). Before assembly, please always check for damage (on rotor without magnet plastification try to push the magnets aside with your fingers). After impact the glued in magnets might have broken loose, sticking to the rotor solely by magnetic force, so that one does not notice right away. During engine run the damage would be considerable. Before placing the rotor onto the engine, please make sure that its magnets have not collected any metal objects such as small screws, nuts and washers. That equally would lead to severe damage.

If you have access to the Internet, best view those instructions online. You get larger and better pictures by clicking onto them and possibly updated information. System list at http://www.powerdynamo.biz
You should have received those parts:
  • stator unit
  • rotor (flywheel)
  • rectifier/regulator
  • screws, battery cables

To disengage your new rotor again, you will need a puller M27x1.25 (part-no.: 99 99 799 00 -Not provided!-).

Note: Never use a claw puller, a hammer or any other device, that will shake the magnets off.

Make sure your motorcycle rests securely, preferably on an elevated work bench and that you have good access to the front of the engine.  You will have to turn the front wheel from time to time for better access.

Disconnect your battery and take it out of the motorcycle. Note that you will install a 12 volts system, so you will either need a 12 volt battery or you use the option driving without a battery. You will still have to replace all lightbulbs to 12 volt ones. The horn may stay at 6 volts.

Drain your petrol tank into a safe canister. Make sure you do not spill petrol. Refrain from smoking. Disconnect the connecting tube under the petrol (gas) tank and take the tank off. Put it into a safe place for the duration of the works.

Unscrew the generator cover and take it off. Disconnect the wires from the old generator, regulator and rewire as follows.
  • the blue wire at generator terminal 61 (which runs to the charge light), gets connected to the red/green of the new regulator (unless you want to drive without battery, in that case do not connect, leave insulated idle)
  • one heavy red (might also be black) wire at generator terminal 30 (which runs to the battery plus) is connected (bridge) to the heavy red running formerly to terminal 51 of the stock dynamo (see next item).
  • one heavy red (might also be black) wire at generator terminal 51 (which runs to the headlights main switch) is connected (bridge) to the heavy red running formerly to terminal 30 (see item above)
  • one heavy brown wire (ground) which is attached to the ground terminal next to the negative (-) brush secure to some other ground point

Integration between the original general electric system (lighting, horn etc) and the new system is at the battery (or should you drive without at the wires normally running to the battery).

Use a hex key (allan wrench) 5mm and remove the two screws retaining the field of the generator to the engine casing. Remove the field. You might need to gently bump its side with a rubber hammer to disengage it.  

The new stator unit is pre-assembled so that you can recognize its structure more easily. To install it, it has to be partially disassembled however. Take care not to damage the paint insulation of the coils.

Unscrew the new stator coil from its base plate (the 3 hex screws) and lift it a little away from it so that you can access the mounting holes in the base plate.

Now put the base plate consisting of the steel ring and the base plate (aluminium) onto the engine block and screw it down with the 2 screws M6 provided.

to enable cable exit from the closed dynamo seat, the adapter plate has a sideways opening and a facility to keep the cable down so that it does not interfere with the rotor.

Also it has a flatened part on its circumference to avoid conflict with the elevation for the magneto.

So make sure to assembly it the correct way with wire showing to the right and the flatened side facing up.

Now put the stator coil back into its position on the plate, taking care not the damage the wires. Make sure that the inner opening of the stator unit slots evenly over the elevated fixing rim of the base plate - otherwise the coil will sit loopsided and will touch the rotor, damaging it.

Screw the coil down with the 3 hex screws M6x30 and tighten. The thick black coil will now show into an about 1 o'clock direction as shown above (picture here shows wrong situation)

Put the rotor onto the crank and screw it down with the provided screw M8x40. Do not forget to place the washer there.. To disengage the rotor again, use a puller M27x1.25, never a claw puller or hammer blows!

The new regulator/rectifier could be fitted under the rear holder for the petrol tank. (On this proposal the customer has used a selfmade unit plate.) For this, unscrew the nut (spanner 13) securing your BMW's tank holder and put your new regulator plate (with the regulator on it) underneath. The regulators cooling fins will face upwards. Put the nut back, do not forget to put the washer back.

You may fit the regulator/rectifier in any other way.

Connect the parts as shown in wiring diagram g-only:


The new regulator/rectifier has a compact plug with 6 positions, of which one is not used. A female plug cover fitting to this plug is delivered. Into this female plug you have to insert the following wires (which have terminals that snap into the plug):
  The two black cables leading from the generator ...

... connect to pins 1/4 of the new regulator (from there equally black wires lead inside the unit). It does not matter which wire connects to which of the both terminals (1/4) as they carry alternating current.

  The new brown cable with the round eye terminal  ...

... connects pin 3 of the regulator unit (from there equally a brown wire goes inside the unit) with the negative pole of the battery or (in case you drive without battery) to ground (chassis).


The new red cable with the round eye terminal ...

Take care:
Wrong polarity will damage the electronics!

... connects to pin 5 of the new regulator (from there equally a red wire goes inside the unit). Here your regulated positive voltage comes out to connect to battery plus, or (in case you drive without battery) to the voltage input terminal of the main switch (ignition lock, German bikes: pin 51/30).

  Make sure that you have a 16A-fuse between battery and vehicle circuitry.

The green/red wire at pin 6 of the new regulator ...

Until November 2007 this wire has been a single wire outside the compact plug.

... is for the charge control light. You connect there the wire that formerly did run from the control light to the original regulator.

Sure that this control only functions with a battery present. Should you drive without battery but still connect the wire, you will see that the light glows even as the generator generates voltage. So without battery, do not connect it.

  The charge light control function is based on a transistor switch and is an additional function. Even if that should fail, the regulator might still be in ok working condition. Simple check: have the engine running, turn lights on, disconnect the battery. If you have bright lights the unit is ok.
  Remarks for 6 Volt systems:
  • There is no charge light control function in our 6 volts systems. Hence no green/red wire
  • The ground wire between plug and regulator body is not brown, but white.


Finally - and before installing the battery and before the first kickstart - please re-check carefully all connections and fitments against the wiring diagram. Do check battery and light bulbs for correct voltage (12V).

Should something not work, please consult our trouble-shooting guide on our homepage. As a first step disconnect the blue wire from the coil and re-test.

* IMPORTANT: During crank shaft repair the dynamo shaft is often machined and gets shorter. The result is a rotor sitting lower, possibly touching now with its rivets the stator coil. The result is a destroyed stator and ignition failure.
For more detail and how to check see (online) here.


Important safety and operating information for dynamo only systems


Safety first! Please observe the general health and safety regulations motor vehicle repair (MVR) as well as the safety information and obligations indicated by the manufacturer of your motorcycle.


After installation, please check tightness of all screws. If parts get loose during run, there will be inevitably damage to the material. We pre-assemble screws only loosely.


Give the newly installed dynamo a chance to work, before you start to check and test.
Our parts have been checked before delivery to you. You will not be able to check much anyway. At any rate do refrain from measuring the electronic regulator other than the output voltage. You risk several damages to the inner electronic there. You will not get any tangible results from the operation anyway.  Check ground connections carefully and, to be on the safe side and for testing, put an additional ground wire from the regulator directly to the engine block.


Never do electric arc welding on the bike without completely disconnecting all parts containing semiconductors (ignition coil, regulator, advance) stator and rotor need not be taken off.


Electronics are very sensitive to wrong polarity. After work on the system, do check correct polarity of the battery and the regulator. Wrong polarity creates short circuits and will destroy the regulator which is for negative earth only.


When you handle the new rotor, take care not to damage its magnets. Refrain from direct blows to the circumference of the rotor. When transporting never put the rotor over the stator. Observe our information relative to transport of the material.


It is a good idea to cover the rotor in a thin layer of oil to reduce the risk of corrosion.


Never use a claw puller or a hammer to disengage the rotor. Its magnets might become loose in the event. We offer a special puller screw for disengaging the new rotor again (see assembly instruction)!


Should the motorcycle not be in use for some longer period, please disconnect the battery (so existing) to prevent current bleeding through the diodes of the regulator. Though, even a disconnected battery will empty itself after a while.


Please do observe those remarks, but at the same time, don't be afraid of the installation process. Remember, that before you, thousands of other customers have successfully installed the system.
Enjoy driving your bike with its new electric heart!