Should there be resistance in the blue HT lead?

[HENRY]

Hi, I am checking and cleaning all the connections on my ETZ125 1987. I have taken the cap off the lead and measured the resistance on my multimeter. The reading was about 001 or 002 instead of 000. So I thoroughly cleaned the cap with WD40 and got the black gooey gunge out from the screw end where bits of the cable had sort of stuck to it. I eventually got the 000 reading which I understand means no resistance i.e. a good current flow. However when trying to get a reading from end to end of the blue cable the reading is still 001/002; should the reading be 000? I cannot see any copper when looking down at both ends. Should the cable be replaced? I cannot get a 000 reading - is this a factor that could lead to my weak yellow sparks instead of fat blue ones as stated in the manual?

Is this a standard size HT cable or an East German/continental/MZ size? Are they available in motorist shops?

I am planning to replace the battery anyway soon, but is this cable still serviceable

Thanks for any advice

[DAVID THOMPSON]

there will be some resistance
less than 1 ohm in most cases
the wire is a compond of carbon and grafite imbeded in a cord like rope
there is a copper wire replacement hard to find and expensive
and may not be legal when you go to mot the bike
these new meters some even read the Resistance of the meter leads
for the test your doing i like the old meters from 30 years ago
dave

some wires have a resistance built in and none in the spark plug
its all designed to work and not cause your radio or TV to go nuts when some one drives by your house
old bmw bikes had the metal shield i think it was required by law
as the mag would really take out a weak tv station

a Bosch mag is a first cousin to a Marconi CW transmitter
ford cars in the 1950's were bad about it also

emergency spark wire for bmw from 1955 to about 1977
was a number 12 wire inside a small piece of new fuel line
worked good when some B hole cut the wires off your motor

[HENRY]

I am checking all the terminals on my ETZ125 for resistance/shorting etc by looking through the Haynes manual, a list compiled by a very useful MZ Riders Club member and a coloured diagram that I obtained with my log book back in 1987.

I hope that my report on any findings with electrical connections will be valuable contribution to other novices like myself.

So far I found that dismantling the HT lead from the screw on plug terminal for the first time ever showed a sticky gunge which I cleaned out. I hoped too much of the lead had not disintegrated at this end. After putting the bike back together, I did a short test run and then rode to work and back: 12 miles. I felt the bike ran better than ever! So I would recommend this job. Originally I thought the lead was intergral with the cap, which is why I had not touched it all this time. I would recommend getting the parts manual which thoroughly shows every single nut and washer etc.

Another thing I picked up was that this coloured diagram (shows 6v one side; 12v on the other) shows terminal 61 on the rectifier with a single green/blue cable leading to regulator 61. From regualor 61 terminal this cable jointly connected with a second cable then goes into a loom to the LVR connecting box and onwards to the charge light I think I remember. However I found that in the Haynes manuals for ETZ125 early and late versions; also ETZ250 early and late; also the excellent list from the club show the opposite where the two joint cables go to rectifier 61 and not regulator 61 - ie simply the other way around! Maybe this does not make any difference, perhaps who knows could comment?

I am still checking through the bike and I will report any findings that might be useful.

[DAVID THOMPSON]

A NOTE
about the charge lamp in dash panel
on a lot of systems this bulb needs to be installed and good
or the charge system will not charge correct
i always try to replace this bulb with the oem bulb
so i do not have a charge problem
this may not apply to all systems with this bulb
but some i have worked on did not do very well
with the wrong bulb
dave

i think what happens is when the key is turned on the bulb
allows a bit of current to flow in to the circuit as a starting
charge for the generator ..once it starts it goes out
as the generator equals the battery voltage....