MZ/MuZ Riders

I am cleaning up my terminals and checking the wiring and I would like to ask for any advice or comments on these two items:

I understand briefly these two names mean basically the same thing. However my 1986/87 ETZ125 colour wiring diagram shows a 'Condenser' together with the points and another 'Capacitor' secured by one of the two rear rectifier mounting bolts under the seat and this is connected by a red wire to the other reds at the fusebox junction.

I would like to know:

1. It looks like the capacitor under the seat is not used on later ETZ's? If this is right then why? If so did it cause problems or was it simply unnecessary?

2. Are the condenser and capacitor exactly the same thing internally? They look both the same from the outside so can they be both used for either purpose?

3. Could I discard the capacitor under the seat and carry on? Does it not matter? (i.e. it is just there for perhaps extra protection?)

There does not seem to be much information about this.

Thanks in advance.

Paul.

Hi Paul
Must say Ive never seen a capacitor under the seat either in real life or on a wiring diagram. However Ive just had a squint ( literally) at Haynes and there does seem to be a capacitor between the red wires and the main earth. Can't see what this would be expected to do apart from fry the electrical system if it failed.

Capacitor and condersor are are the same thing, they may look the same or they may look different, but in this case I would expect them to look similar ( cylindrical metal thingumy, not to be confused with the indicator flasher cyclindrical metal thimgumy )

And I can see no reason whatsoever for the extra capacitor!

Ive added a copy of the schematic to see if any electrical bods can see a reason for it

i think its to get the output from the voltage regulator under control...

some of them can make a bit of electrical NOISE that can wreck a TV picture or a radio program as you motor
through a town
and some of them can be LOUD

RFI FILTER is the term

https://en.wikipedia.org/wiki/Filter_capacitor

Contact suppression
A wound plastic film mains rated capacitor plus series resistor are incorporated into a single component envelope for convenience and robustness. This reduces switch arcing and RFI. The most common combination of values is 0.1 µF + 100 Ω.

dave

I've found a reference in my MZ Repair Manual, April 1986:

"When operating the 3-phase current dynamo without battery, a capacitor of 2.5uF, 50V must be connected between earth and terminal 51 (presumably on the regulator). This is available in the ETZ as standard equipment".

Extra note to this adds:

"Not applicable to rectifiers with diodes of an inverse voltage of 200V from August 1986".

Why would this capacitor be fitted for an odd purpose like this - why would you not need a battery?

This bike was made in East Germany before the Berlin Wall came down so was it to do with people having no money to buy batteries? What other reason could there be, I wonder?

Any comments welcomed.

lack of money makes batteries a bit of a pain

i used to run a big computer capisitor on my bmw r50s ( magnito ingition
from 1975 to 1998 worked fine and no battery acid to eat the frame up
it was a spair bike and not used often but was ready to go if i needed it
if i used it on a long trip i would use a 6volt gel cell off some of the backup power supplies on computers..
so i had lights if i stalled at night so cars could see me
dave

Hi, HENRY -
You have my sympathy - as the owner of an even earlier ETZ125 Luxus I find myself in a similar position regarding the lack of information about these bikes.
My particular bike is 'C' registered (Apr.'86 UK) and was already (very) 2nd./3rd. hand when I purchased it from a workmate in Nov.'93.

As you have already worked out, 'condenser' and 'capacitor' are pretty much interchangeable in a literary sense - 'condenser' being an old description used by the automotive industry but dropped many years ago in favour of 'capacitor', which was regarded as a more accurate/universally recognised description.

HOWEVER - the capacitor under the seat on your bike ( - mine also has one, by the way !.....) has a different rating and part no. to the ignition capacitor, which makes it NON -interchangeable for that purpose, in my limited understanding of these matters......

Do you have an OE Owner's Handbook/Instruction Manual ? The (downloaded from the internet) copy that I have shows "Electrical equipment under the dualseat" in a line drawing fig. 35 and lists the capacitor (item #3) as "Interference supression capacitor".

HTH,

"Not applicable to rectifiers with diodes of an inverse voltage of 200V from August 1986".

The first rectifiers were not that strong as the later ones. They only had 100V .
The condenser was to prevent the rectifier from damage. I am not an electrician, but I think that high power would have burned the rectifier. The condenser should prevent this. After some years, they put a stronger rectifier into the bike, so the condenser was no more necessary.