MZ/MuZ Riders

Hi,Alex here, I'm new to the forum.
I'm near the end of fixing up a 1986 TS125 that has been off the road for 20 years.

There is one problem I've not resolved.
When the sidelight or headlight is on & I turn on the indicators, the headlight / or sidelight get dimmer & then back to normal.
The tail light has the same issue.
I've cleaned every earth I can find but still no joy.

Any ideas?

modern lamps have a higher wattage and maybe overloading your dyno/genarator?
take all the indicator lamps out and test again with the indicators on , maybe theres something with the indicator relay?
if its still the same then get someone with a multimeter to test the output of the gen/dyno.
if the bike has a regulater/rectifyer then it maybe that also, I believe ac current will rise and fall with the revs and dc current will be a constant,

if the bike is very old check that some one in the past has not wired something wrong
also check to see if the turn lamps are of the proper wattage
if it has brushes make sure there in good order and where they run is clean and not glazed
also if 6volt that the battery is good and properly charged
dave

Thanks.
All bulbs are the correct wattage.
I took thebulbs out but this stops the flasher unit from operating, so the lights were ok trying this.
Battery reads 6.5 volts with the bike running.
I cleaned the earth inside the headlight that has about 6 earth terminals on it.
Looks a bit better now although there is still ssome dimming of the lights with the indicators on.
Is this the norm?

More problems I'm afraid!!!

I've been cleaning the terminals & contacts at the voltage regulator.
I've removed the dynamo brushes (which look good) & cleaned the rotor they rub against
I've also done the dynamo polarity fix just in case it was this that was causing the issue.

Now the battery isn't being charged when the bike is running & the battery light is staying on when running.
I did accidentally short the 2 right hand terminals on the regulator when cleaning the contacts & I heard a buzzing sound.

Any ideas guys?

I would change the electomechanical regulator, for an electronic one, as these use less current. On ebay at the moment is one from Hungery of the type I use on an etz251, to good effect. I cannot vouch for the supplier, only the part. If you search on German ebay look for MZ reguler, just whatch the cost of postage. A 6 volt mechanical reulator on German ebay is currently costing 70 euros, electronic between 15 and 40.

Are there any checks I can do on the dynamo to see if this is ok?

Try checking here :http://www.sweller.co.uk/mz/mz_maindex.html under the 6volt section. If you haven't already I would recomend you invest in a good quality multimeter.

if you have extra flasher try a new or different one
the old one may be bad in its parts or wiring and sending voltage and current to the wrong place when it cycles

if you can take the cover off the old flasher with out damage
give it a shot of cleaner and get the vermin out of it....

maybe some thing hiding in it left over from the BAR in the star wars movie.
it is 26 years old that's enough time for green slime to learn to talk....or at least cause problems
dave

I think the flashing problem may be down to nothing more than overloading the electrical system. Sweller (see link on my previous post) list the dynamo output as 60 watts. If you then consider the following:
Headlight 35w
Rear light 5w
Indicatior light(x2) 36w
total 76w
and then add in the unknown wattage of the flasher unit,ht coil, and voltage regulator, its not suprising that the lights will flash when the indicators are on. The battery is there to feed extra current into the system when needed,so if it's at all discharged you will notice the flashing . I've seen this happen on bikes of all makes. The worst was a Jawa 350 I had, the engine would cut out in counter point to the indicator coming on, making for a very entertaining ride around a traffic island!

had a Harley Hummer in the late 1950's it was a bad copy of an DKW rt125
it had a 6 volt system
we ran the coil and points on it from a 6 volt car battery on the luggage rack..
and charged it every night.. the brake lamp also from the battery
the rest of the bike ran from the main system
AND YOU TRIED TO MAKE SURE YOU GOT HOME BEFORE DARK

6 volt systems stink
I also had a BMW R27 250cc single
its down fall was it had 6 volt points and coil system
and we used the BIG 6 volt battery on the luggage rack again
DAVE

I removed the regulator from the bike & got it tested by a tech at work (thanks Bill) & he found no issues with it.
I fitted it back on the bike & the problem has now gone!
When I rev the bike the charge light now goes out.

All the other lights seem a little brighter now as well so maybe I had a poor connection somewhere?

I 've just taken the bike for an MOT & it passed

Thanks for all the help guys!

Good to hear that your now on the road, enjoy

if you plan on keeping it long term
one of the modern 12volt systems may be a good idea...
if it gives you more problems

i would love to have a BMW R27 with 12volts
but the only thing about an R27 is its as rare as my rt125 here in the usa
dave