An Example of burnt points?

[Blurredman]

I was doing some general investigation and comparison between bikes, and discovered my Trophy points look presumably what might bed considered 'burnt'.

The bike displays no signs of running rough during idle or even under load. I haven't actually even looked at the points for about 3,000 miles so presumably if this is a symptom of a problem then I have come upon this relatively early.

I will try to test the capactitor as best I can, if I can, but before that start the bike up in the dark and try to see any abnormal sparking behaviour.

I did smell an electrical smell (smells a bit like cat wee) when I opened up the generator cover, and it was coming from the wound resistor that is fitted on 6v model MZs. The official MZ service manual states that such a resistor should not have a charred insulation varnish, but it does appear possibly that it does. Unfortunately I can't find specific examples to identify more clearly what the result of 'arching' (on the points) looks specifically like, but I do think I have that. I will also test the resistor, though phsyically it doesn't seem to have changed much (if at all) from what it looked like when I first started using the bike 4,500 miles ago. I was actually using the bike briefly before I checked behind the cover so it's possible that the smell is just a natural byproduct. After all, I notice the voltage regulators also smell like this ordinarily anyway.

Thoughts, guys?

[Puffs]

Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

[Blurredman]

Well in the persuit of looking at another bike, I swapped the condenser here on the Trophy with my ETZ300, and found both bikes spark about the same way at the points in either configuration. So I think we're okay here and I'm just making an issue out of nothing. I'll just file/sand the points on the Trophy.

As for testing condensers I found an instruction on the Internet that says you can test condensers by putting a multimeter on '20M' and then probing the item. If you have a good condenser than you will find the value slowly build from zero up to the capacitence value (in this case 20k). If you find the value jump straight to 20k, or go 5k, 10k, 15k or display zero then it's broken, at least in a cold state test - it needs to build in a linear manner, 5k,6k,7k etc.

So with that I tested my spare capacitors and they check out too which is nice.

Condensers on the 6v vs 12v are the same item, the only difference being the older condensers have a screw in terminal as opposed to a nut. Not that it matters other than an interesting thing to point out design design change as below:

'New' style.


Old style (internally threaded)

[Gerryman Ts125]

One of the main reasons I stopped driving My Ts 125 was having to replace the contact breakers often ( I did hack it for six months) and it ate contacts. Never had to replace a condenser or the brown spiral wound resistor.. But in those six months I had to adjust the regulator box contacts four times. I had to renew the regulator box twice ( I was covered by Mz for the first failure) but not the second, as it melted the points blew the condenser and resistor .
Used a old Volkswagen 6v one, and that worked fine, but overcharged the battery.

Had to fill it up with Scottish tap water (as good as distilled water, almost a clear whiskey). quite often.

One of those reasons It sat unused for over thirty years. But in that time I had a few others.
But not with contact breakers. Mostly 250 Etzs. They were just brilliant with very few electronic problems, apart from batteries and sparkplugs..

Have you investigated your old points box??

[Blurredman]

Hi Gerryman,

There is only once where I have had to legitimately replace contact breakers and that is because one of the contacts flew away (I guess the glue gave out).

Despite my thoughts about replacing components in question, I always put the original back if I can prove that they are not at fault. So my machines are all running as original as electrically possible. I have had to replace a voltage regulator on my ETZ300 (and a stator, but that was my stupid mistake that required this to be replaced) and a coil on my 251.

So far the Trophy in question in this topic has had no electrical problems other than the brake light (requiring a new + side wire from coil), and a replacement coil within 4,200 miles (coil and brake light wire were early problems fixed within a few hundred miles of putting the bike together).

I'm not sure what you mean by points box? The regulator? I have several of both 12v and 6v so although I have had one fail on the ETZ300 I never did look into it, I just replaced it with an identical item. My 251 has an electronic voltage regulator that was fitted to it before I bought it. I don't want to replace components unless they break so I left it on. Besides which I like to try to keep that bike going for as cheaply as possible so if there's no need to replace components I won't. I've not so far ever had a capacitor/condenser break on me yet, either!

[Gerryman Ts125]

I did 19000 or odd mile on my Black Ts 125 in the first year after I purchased it from new. Most of those miles were in all sorts of rain ( mostly) in Glasgow and surrounding city's (within thirty miles) I was classified as a small bike by my courier companies.

Had to learn quite quickly how to fix problems on the hoof (or tyre) but the Ts soldiered through. I had multiple failures of electricals.

.Mostly figuring out how good Mz built their bike ( once I had covered the coil and sparkplug and lead with rubber to stop water ingress.
But the regulator box, even though I tried to keep it dry ( by using a plastic box/ cover, did fail internally.

Hence one melting my electrics ( coil, points, resistor wiring harness, battery with fourteen volts

But before my regulator box problems I had to adjust its contact breakers more that once (as my Mz dealer put it) I should have let them adjust it.

So maybe your problem may stem from in there. As my one did arc quite a bit.
Before I firstly used a cable tie to hold the main fuses in situ.
Then replaced it with a better waterproof/ non vibration item.

As my first and original Regulation boxes contacts had worn by using my lights constantly over a four month 3400 miles.

[dave47]

As George123 has said recently, you can eliminate burnt points by fitting a Vellerman k2543 unit which also eliminates the need for a capacitor. Unfortunately it seems to be only available as a kit of parts. If you are not good with a soldering iron Gammatronix sells a ready to fit unit but at a much higher price. I have one on my etz and it completely removed sparking at the points.

[klemmy]

Blurredman, are those the same condensers, the one next to ignition breakers and the one under the seat?

The "new style" is the one next to breakers 0.22 µF 250 V

The "old style" under the seat 2,5µF 50V

Correct me, if Im wrong.

[parrbd]

I am still running the original points in my 1984 ETZ250 that I bought brand new. I bought a spare set of points about a decade ago but have not needed to use them yet.

[Blurredman]

Hi Klemmy, I was just making a reference to the new (etz plus) vs old (es/ts) 20k ohm capacitor/condenser terminal arrangement.

As for your question concerning the one under the seat, this is different. The one under the seat is required on ETZ's < est 1986, as they have 100v diodes on the rectifier, >1986 ish the rectifier board has 200v diodes which negates the requirement for the extra capacitor under the seat and thus later etz's don't have it. You can identify later rectifier boards by a 200v stamped on the yellow sticker/paint. But it is required if you do not have that.



I've never used such contact breaker kits that reduce ear though I know of them well. I have several sets of contact breakers of varying quality (oem and aftermarket) and have yet only had to replace one where the lower pad actually disapeared! (I guess the glue or something let go). Normally just filing/sanding them is quite sufficient!