This page is about the BMW motorcycle models R51/3, R67, R67/2, R657/3, R68,
R50, R60, R69, R50/2, R60/2, R50S, R69S, R50/US, R60/US, R69US.
A full description of the install is being prepared now and should be out in
early 2005.
This page is only to supplement the existing information on the Mz unit.
This page isn't intended to be any permanent thing, only until Joel gets his own
web site up and running.
Replacement for the Bosch magneto
The unit is made in the Czech Republic and is very high quality. It can
be purchased in two versions, one to replace both the generator and magneto, or
just the magneto alone. It is imported into the USA by Joel Rapose and his
email is jrapose@thegrid.net Joel has a
service to install and test the system on your bike, ask for current rates.
He also has spare parts and is willing to assist with advice on installation.
I will post photos as soon as good quality ones are available.
The web site for the makers is
http://www.dynamo.mz-b.de/bmw/bmwmain.htm
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A collection of emails
The MZ-B system does not use the battery for ignition. The alternator
that you get with the MZ-B system has two windings on it. One
winding for the battery charging / lighting and the second winding is for
running the ignition system. It will run just fine without a battery in
the bike.
Slight modification to my statement below. The electronics in the
electronic advance module does require 12 volts from the battery charging side
of the alternator. Very little current, however. The spark energy
does not come from the battery. It comes from a second, separate, winding
inside the alternator as I stated below.
NOTE! If you do run the MZ-B system without a battery, DO NOT allow the
battery terminals to short! The MZ-B system uses a permanent magnet field,
unlike the /2 generator or alternator. Hence it will produce voltage if
it's spinning. Best would be to put a electrolytic capacitor in place of
the battery. 100 uF or more, rated for 25 to 50 volts.
-Klaus
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Yes, it is a translation problem. But it's not with the translation
from some other language to our own. It's with our tendency to modify our
own language through common useage. We confuse ourselves in the process.
It's like this. There are several kinds electrical generators in general
use. They fall into two basic categories, those that generate direct
current and those that generate alternating current.
We tend to shorten things in common use, therefore an "alternating current
generator" becomes an "alternator". We then use the word "generator" when
referring to the more 'old fashioned' direct current generator. The
type of generator used in the MZ-B system is a permanent magnet alternating
current generator, commonly called an alternator. It consists of a
magnetized rotor which spins , and a stator with field windings, which remains
stationary.
Nortons, Triumphs, and BSA's from the mid-sixties through the eighties use a
similar system manufactured by Lucas. The only significant difference
being that in the Lucas system the rotor spins inside the stator, whereas the
MZ-B system is the reverse of that . The alternating current
produced is converted to direct current by a rectifier in the Lucas system, and
a zener diode is used for voltage regulation.
A capacitor is available as an alternative to the battery for those who
wanted to use it. With the capacitor correctly installed no battery is
needed to run and you still retain full use of the lights. It works
quite well but there are some minor drawbacks; at least in the Lucas system.
A. The engine won't start if the lights are on, and...
B. The lights tend to flicker at low rpms, getting very dim at idle.
I can't think of any reason a capacitor such a Wolter suggests wouldn't work
with the MZ-B system. But if a capacitor is used to replace the battery,
you might experience the same drawbacks as with the Lucas system. But
hopefully not, as the electronic voltage regulator might do a beter job than the
Lucas rectifier and zener diode.
Herb Mann
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HERE IS MY CURRENT UNDERSTANDING
1. This System replaces the original Magneto and 6 volt DC generator
2. The new 12 volt Alternator is a 2 in 1 unit. it has windings
for the lighting circuits and a second set of windings for the Ignition
circuits. The two systems are independent.
3 The new system replaces the points with a Magnet and sensor like a Hall
Effect unit.
4. The new system is delivered with a coil unit and ignition control.
Regulator/Rectifier and spark plug wires
Jerry Cook
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I don't think I am so fond of the idea of running without a battery...it
seems plasable but not on MY bike....
What I would like to try is to install a damper on a R50 or R60 like the R69S
has....
The MZ-B alternator is so much shorter than the old generator that I think it
would work without changing the cover.
By using the alternator tool nut as a mounting base for the damper it mounts
great... and I think there is clearance.
I have dampers on both my R69S bikes using rubber and new disks from Vech and
they work super...I check them every 500 miles or so, but have yet to see any
wear or rubber deteroation.
Joel Rapose
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Ron - Yes, MZ-B also sells an ignition-only system, if you already have a 12v
conversion (or an original 12v system). I have this system, though I
haven't installed it yet. It will take some extra work to mount it, as my
existing Motorrad Elektrik alternator conversion takes up the space under the
tank that the MZ-B system needs. I think I'll be able to get everything
under there, but I will have to make a new mounting plate. Next winter...
Paul Evans
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Visual directions, short version of the parts on the engine
This is the bare case after you remove the BMW magneto and
generator.
MZ Ignition sensor plate mounted
The MZ stator mounted with the ignition wire hooked up.
Proper grounding position for the stator.
MZ ignition rotor installed.
The is the all of the MZ components mounted under the front
engine cover.
A close up of the MZ alternator rotor.
This shows the only timing mark of. See it lined
up with the MZ sensor?
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