HELP!!! MZ ETZ

[davenickmills]

Hi

Ive rebuilt the top end (barrel + piston) on my 1990 MZ ETZ 125 but now it wont start.

I had the generator off during the rebuild (the outside part with the wiring going to) and got the 3 black wires in the wrong order when it went back together but have since corrected it but it now wont start when the ignition is on and i kick it over. The crank turns freely and the points connect, and there is a voltage going to the coil although this does not vary with the points opening and closing. There is no visible spark at the plug. The bike ran before I took the engine out.

Does anyone have any suggestions as to where the problem lies please? if you are in North East Wales area you are more than welcome to come and have a look.....

Its my first bike, and as you can probably imagine im anxious to get it going again and get on the road!

[TS2Fifty]

From the sound of it you've still got the wires in the wrong order. Why are they all black though, on my TS they have tracer stripes on them.

If you have definitely got them right (double, triple & quadruple check!) then the only other reason the voltage at the coil wouldn't drop is shorted or non-opening points (the coil generates it's HT spark current at the moment the points open or LT voltage is otherwise cut). To be honest I reckon the wiring must be mixed up as that is the only thing you've really disturbed. HTH

[mr.combo]

I agree that it is probably electrics. To find out what goes where you might be best to invest in a proper manual. See the MZ Riders Club site at http://www.mzregalia.com/page4.htm for details.

[davenickmills]

I agree that it is probably electrics. To find out what goes where you might be best to invest in a proper manual. See the MZ Riders Club site at http://www.mzregalia.com/page4.htm for details.

Thanks for the link, ive duly ordered one.

[davenickmills]

From the sound of it you've still got the wires in the wrong order. Why are they all black though, on my TS they have tracer stripes on them.

If you have definitely got them right (double, triple & quadruple check!) then the only other reason the voltage at the coil wouldn't drop is shorted or non-opening points (the coil generates it's HT spark current at the moment the points open or LT voltage is otherwise cut). To be honest I reckon the wiring must be mixed up as that is the only thing you've really disturbed. HTH

lol I wish they had! all three are black, which matches the loom diagram I've got from a Hungarian website. My mates an electrical engineer so he got roped in to check and hes confident they are good but ill get them checked again on Friday.

The points open and close ok. Is there any way to check if they are shorted? As you can probably tell Im not an electrics guy! hoping to get it running for the show at Llangollen on 2nd/3rd August.....

---

just been speaking to my mate, hes asking if you would be able to tell us where each of the three black wires feeds to please?

Thank you

[zedhead]

Going from memory, the three black wires come from each of the alternator stator phases and go to the rectifier under the seat. It doesn't matter about the order. You should have two more wires which supply voltage to the rotor, one +12V-ish and the other ground. Then there's the points wire which has a spade connector on it. It sounds to me like this one has been fitted somewhere it shouldn't, say alternator. The cables usually retain a set shape which gives a clue to where they were originally fitted. One way to check, perhaps, is to have a spare spark plug in the plug lead&cap with the plug body touching the engine, then turn on the ignition and then disconnect each wire one at a time. When you see a spark at the plug, that's the points lead, because once the coil is disconnected (usually when the points open), the field in the coil collapses and a spark is produced at the plug. The fact that the coil is permanently energised suggests that the points aren't opening (so you can easily replicate this by taking off the points lead and then touching it to earth and then removing it again) or the points cable is connected to something which has a current path to earth, like the alternator.

There again, I could be wrong as I'm working from memory!

Let us know how you go

Karl

[saxonetz]

hello, i have a manual in front of me, according to the diagram, as Karl says, they all go to the Rectifier to 3 different points, this in turn joins all wires up and connects to a Green?Red wire, this wire then splits, 1 wire to the ignition switch and the other to the Regulator, good luck, vin.

[davenickmills]

thanks guys, im up at the workshop 2morrow to have a look

[bisphaman]

MZ Riders Club have a North Wales and Cheshire Section and website. Might be worth a look if you're not already a member.
They have their own forum which it might be worth posting on to get some local help or knowledge.
Best of luck with the ETZ.
Regards,
Simon Greenwood


http://www.mzridersclub.co.uk/nwc/index.html

[davenickmills]

Hi

Ive checked the wiring loom and its all right. Ive fitted a new coil, and it discharges at the correct time, but im waiting for a new ht lead and connector to arrive from AKF.

Ill check out the club now, i wasnt aware one existed!

Thanks for your help guys

[TS2Fifty]

So what's happened there then? I thought the coil was permanently powered up & that needed sorting, or is that fixed but the coil got burnt out? I'm confused.com!