Das MZ Forum für MZ Fahrer

Hi guys,

Sorry I speak in English- I don't know German very well at all (in School we didn't care for foreign languages- later in life I realise this is a regret- but children are as they are..). So I hope this is acceptable? Or I could use Google Translate or something to convert to the native preference? Please let me know.


This is my first post here, I am predominantly a user in the mzriders.com forum as the language there is defaulty English, but alas it isn't a very populous forum and indeed it does have some holes in the knowledgebase that I thought mz-forum.com can help me with.

I am the proud owner of 3x MZ's, included in my signature. Pictures wanted then they can be supplied.
I do like to travel, and have taken my 251, which was a £100 piece fit for a lake with many many problems that I eventually overcame, to Istanbul once for just one of my many holidays abroad I have had in recent years (the last two years not withstanding).


So, Fallen into my lap in July this year was an 1974 (or at least, that was when it was registered) ES250/2 Trophy. I had always wanted one for many years if indeed simply to ride and experience even for a short time. I have made a very long process of basic rejuivination of this machine here: https://mzriders.com/viewtopic.php?f=5& ... 11a6d7e403
If people want the thread copied to this forum then that is fine, but for now it was a bike in total bits and last on the road since 1983- to cut things short, I assembled it to find out what parts were missing, and In the mean time I also re-built the engine (except I did not touch the piston or barrel), with bearings and crank re-built as it had been in a flood in 2019.

The bike is together as much as it can be for the minute and I have no immediate plans to make it look 'good'. My main concerns at the minute are understanding it's problems and acting on thm accordingly and simply enjoying the bike for what it is at this stage of it's life. One day I may indeed restore the bike fully. But I haven't money at the minute with major life events (wedding and children) have taken all of my money, and somewhat also just as importantly, most of my time! So a simply bike that runs and is fairly reliable and something that I can just enjoy for now is what I want this bike to be.


Two things I have not overcome yet + 1 question:

1) the top bracket mount for the left hand side panel is missing from my bike. You can buy this piece from various suppliers in Germany, but I have a welder and a brother who can weld. If I had the dimensions and measurements I could fabricate my own. The main issue not to buy one is postage/import costs. One suck supplier of example of this item can be found here:
https://www.ost2rad.com/MZ-Spare-Parts/ ... s-250.html


2) After tracing back air leaks and for the most part (have yet to totally clarify with carb cleaner), the bike is running great.. It is slow sure, but the power and torque are linear and very comfortable and civilised, but the problem I have is getting a reliable idle on the bike.
I think this is due to the way the throttle slide works on the handlebar? I have lubricated cables and throttle assembly, but if I raise idle to a nice speed with the adjuster on the carburettor, the next stop it can be higher, what's more the speed of the engine climbs when the clutch is pulled in and can make changing gear difficult due to this high speed. So- the idle is set down a bit, and requires me to keep a hand on the throttle to make sure it doesn't die (because I think pushing the throttle forward closes to the main slide too much?) and making a rich idle. So.. alas changing gear is best whilst pushing the throttle forward in order to close the air slide? It is something I have not encountered before, is this design? And should I just get used to it? Or do I need to make more appropriate adjustments. The pilot screw on the carburettor is currently 2.5 turns.


3) Additionally, now that I think about it- the brake light (standard rear drum switch) only comes on when the engine is running. I thought this was a standard DC item and like all other bulbs on the bike this should light regardless as to whether the engine is on or not. I've checked this and get no voltage with the ignition simply on. Moreover, at lower rpm (basically when I'm simply idling), it fades away into nothing. So is the brake light indeed AC? The wiring is completely standard...


Picture of the bike taken the other night for interest

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

Hi Redman,

welcome to the german MZ forum. Nice "EisenSchwein"

First of all it is nice that you like to ride your MZs and use them also for longer journeys (Istanbul). I was there with even an older ES than you have .


1) I don't have the dimension right now in front of me, I will check with my bother. He's on site.

2)Concerning your idle issue:
please verify when adjusting your pilot screw that you start from 1.5 turns (out) onward. In addition to the air leakage (big issue for any two stroke engine) make sure your float in the carburettor is proof and well adjusted. Otherwise you need to bend him to the right fit. Just check for if the float fine. You got any manual for this fix?
Yes the throttle slide needs to be working well and ideally should slide to "close" position automatically by the force of the spring (in carb). Please check the way your Bowden cable is mounted and in case also lubricate this one in addition. Check if your throttle slide (in carb) works well (spring is fine, slide not worn out - too much tolerance).

3) Is your battery alright?

Kind regards,
Emanuel

P.S.: probably you will get more help if you write in german: Please copy and paste your text/ answers here: https://translate.google.com/?hl=de It doesn't work too bad usually.

Das gilt auch für die Deutschen hier, wenn euer Englisch nicht der Hit ist, kopiert einfach eure Antwort in den Google Übersetzer, dann passt das schon so halbwegs.

_________________
Rundlampenschweinchenliebhaber-Clubmitglied Nummer 009
22.000 km in 4 Monaten auf 2 Rundlampen durch Russland & Zentralasien, http://mz-forum.com/viewtopic.php?f=12&t=45335

welcome to the forum!

the brake light normally works on battery, so perhaps you should check the wiring and the brake contact, if it is still the original one.

apart from the idicator lights this one should be ok for your bike:
http://www.roadsmile.com/images/mz-150_brown_0.jpg
-->brake light: Nr. 22, so it should be connected to the ignition coil (15), perhaps someone has changed this in the past.

Absolutely beautiful introduction, should be preserved as an example in my opinion .

I really like your bike, and in all honesty I hope you won't change anything cosmetically. About the brake light problem: I highly recommend you check your battery, and also you should probably take a look at the bulb seating and the switch itself. A friend of mine once had a similar problem on his MZ, his problem was the result of a corroded light socket which didn't really help conductivity...

_________________

Such MZ type was manufactured from February 1967 until March 1973. So 1974 is related due to the date of registration. You can check the date of production by having a look to the generator, ignition coil, the rear of the head light, inside the rear light and a lot of other parts like IV/72 or 10/72 for quarter or month and year, when the number plate is without a year of construction (export model) and when the documents are getting lost.
Also frame number and engine number give clearance of the true bike age.

3. When the stop light won´t work or glow only a bit, please check the whole electric cabling. A short circuit could be the reason, also corrosion especially the contact nail inside the rear brake causes often a potential drop when covered with dirt. Is there a 6 volts bulp installed?
2. Often a bend along the inner Bowden cable causes a hard steering. Remove the bowden cable and check if the inner cable can move free. And of course this kind of handle never runs that easy as the wrapping type.
Check also the skimmer in the carburetor, clean everything with care and bend according the sketch below. (note: the small pin must be compressed and the skimmer gasket must be removed frome the flange when measure the distance of 27 mm)
There is a small spring between spool and and gas bowden cable bracked guarantee a sufficiend idle when release the handle. Check if this small spring is still installed. Twist the handle over the spring you can close the airflow completely and
stop the engine. Than check the gap in the carburetor when the throttle is in lowest position. There must be a narrow gap of about 1 mm.

1. Fährt jemand rein zufällig demnächt nach England und kann so ein Blech mitnehmen? Oder hat jemand die Maße parat, da ich erst am Wochenende wieder bei meinen Mororrädern bin.

Greeting
Georg

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Rundlampenschweinchenliebhaber-Clubmitglied Nummer 009
22.000 km in 4 Monaten auf 2 Rundlampen durch Russland & Zentralasien, http://mz-forum.com/viewtopic.php?f=12&t=45335

Hi guys, First off thank you very much for your interest. It is very helpful to a beginer to the mid-year MZ's like me.

So far although I have my experience with MZ's, the ETZ line is all I have, so it is interesting to see these intricacies that the earlier vehicles had. And I see the reasons for them (such as the retarding starter weights which are not fitted on my bike and the throttle closing mechanism to prevent surging. It shows these mid-year MZ's were really made for a man who rode all year and had no car and these features make the bike very clever (yet simple) and the experience to the user much nicer (esspecially in the winter). Very intruiging!

I will look up the full year of the bike as you say Munin, with use of mold/stamp dates- Good idea! I only went by the registration as at this point that was all I could go by- British documentation of vehicle does not include the vehicle creation date, only the registration for road date- which does cause confusion sometimes in specific applications.

If it does interest anyone at all, I can of course convert my mzriders.com thread to German and make it so on this forum too. Of course one would have to keep in mind that the progress of the thread is backdated and resolutions to early problems have been saught and utilised so might seem a bit backwards initially..


- The cables (including throttle- indeed all) I have lubricated- they are much smoother and resistence free compared to what they were.

- I had an idea about the countering throttle springs.
Foremost - I do have the spring in the handlebar. My thought was that the spring in the throttle assembly (at the handlbar) was under no pressure since it was dismantled in 1983. However, the carburettor was in one unit, and thus I think the spring in the carburettor was under compressed pressure constantly since 1983. I thought maybe it's force was gone. I measured the spring and it read 53mm. I stretched it to about 61mm. I started the bike and the idle does seem to be more consistently falling in the same place. I have yet to actually ride the bike so I can't quote how well this has effected the idle running however. I will also check for about 1mm of slide opening. Thanks.

- I have the original ES250/2 Trophy service manual (original English printed book) - and have confirmed with the ETS manual (with ES250/2 trophy suppliment entry) that I have the correct jets and the float level is correct open and closed and valve is working properly, including the 1.5mm packing between the float valve and base which it screws into. I am using a replacement (new) float I had spare because the original one was cracked and had ingress of petrol into one of the floats. So that's good. I have the main needle on the 4th slot. This seems good to me for the lower RPM/riding speed torque. I can change this on the fly if needed though and experiment, though the spark plug condition looks good.




- I bought the battery new in July. It is true it hasn't been used much since then, but the battery has about 6.3v. Not quite the ideal 6.4v, but I can confirm the bike does charge, though it is not so hot at charging with the lights on. I have last night cleaned the voltage regulator contact points to see if this might help (have yet to measure with my multimeter though)- but I know for certain the bike charges well with lights off so that's okay for now.

- I can confirm that the brake light switch is connected to ignition via coil- standard wiring - and has no resistence in the wiring itself indicating possible corrosion issues. The bulb is indeed an 18w 6v bulb, which is in good physical condition and corrosion free, as are the wire terminals and bulb holder. However- one thing of note is that the inner drum contact (switch) is not in the best condition corrosion wise - It is possible that with just more use the corrosion will rub away and the issue might sort itself, but.... yes I will clean it up and make it free from dust and corrosion when I next have the wheel off. The wiring looks good and original.


Thanks again guys for your help! I appreciate it!

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

Forget the stupid original throttle with the sliding piece and convert to a modern throttle. This increases the drivability of the motorcycle extremely.

You can easily check the switch inside the rear brake by loosing the pin terminal at the outside first and connect with ground. If the stop light shines bright the switch is causing the problem.
If not, wire a temporay cable from the brake switch to the stop light and also from the stop light to the battery and to detect if there is any failure in cabling. The ignition lock seems to be in good condituion because
Stoplight and and ignition coil are at the same pin 15/54 and your ignition works well.
I think the battery is not the problem, because a low charged battery can not start the engine and as far as I understand all other electic consumers are run well.

Greetings
Georg

_________________
Rundlampenschweinchenliebhaber-Clubmitglied Nummer 009
22.000 km in 4 Monaten auf 2 Rundlampen durch Russland & Zentralasien, http://mz-forum.com/viewtopic.php?f=12&t=45335

Übersetzt aus dem Google Übersetzer!

Danke - Ich habe vorher darüber nachgedacht, eine TS / ETZ-Gasklemme und ein Rohr anzubringen, wenn ich weiterhin Probleme mit der ursprünglichen Gaseinstellung habe, und dies werde ich möglicherweise tun, wenn es zu einem Problem wird. Ich glaube im Moment war es mein Gedanke, dass die Feder im Vergaser nach 40 Jahren Zusammendrücken nicht stark genug ist. Ich hoffe, dass ich bald darauf fahren kann, um dies zu bestätigen / zu bestreiten. Es gibt auch das andere Problem in Bezug auf die Gaszüge. Vermutlich müsste auch das Originalkabel geändert werden. Ich habe Ersatzkabel etz250 / 251 - würden die bei einem Umbau passen?


Ich hatte im Moment nicht allzu viel Zeit, in die ES zu schauen - ich nehme an, zumindest die Bremsleuchte funktioniert, auch wenn sie suboptimal ist .... - Gestern Abend bin ich von meinem ES-Projekt abgewichen, um die kaputten zu ersetzen Innendichtung meines ETZ250 Hauptbremszylinders. Aber ich habe hinter die Rückleuchteneinheit des ES geschaut und IV 72 auf der Lampenfassung gestempelt. Das sollte ich jetzt wohl durch einen Blick auf andere Komponenten am Rad bestätigen (immerhin hätte man ja irgendwann mal die Lampenbaugruppe tauschen können). Aber das sieht vielversprechend aus - sehr interessanter Hinweis auf das wahre Alter der Maschine!

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1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

I am completely with you

_________________
KEINE PANIK

P

Hier immer die neuesten Rennberichte: 4h Classic-Endurance in Oschersleben 2023

I-A-L Racing-Team "Idioten am Limit"

Mein Guzzi-Renner: Der Etromit

best throttle ever, albeit expensive. It is also available with two pulls for separate lubrication. http://www.kc-engineering.de/aid-318-Ma ... br-br.html

I've been tracing down the air leaks still on the air box. It appears I need two washers between the airbox and the 'electrical items holder' clamp. I have air sealed the outter side of the box fully now with seals (1/2" tap washers) on the airbox through bolts (where the thumb nuts screw onto) and will be looking into putting washers between the two clamps accordingly soon.

I think I have a small leak on the tube to carburettor intake mouth, maybe just clamping down more on the clamp will resolve this- but also possibly brake cleaner is coming into the top of the carburettor slide ?

This item:

is to remove air from getting in through the top slide? If so, I do have this item but it is not fitted- so that could potentially also be a small source.



Electrical: I haven't looked into the brake light- it kinda works somewhat fine (just not at idle) at the minute so I am focusing on the 'more important' items like the running. I removed the indicator switch unit (because the bike in it's many parts didn't also come in the boxes some indicators). But in doing so it seems both the charge light and the neutral indicator light seem to be a mirror image of themselves and only work when the engine is running, and are both acting as a neutral light. I obviously removed the wiring for the indicator switch unit, so therefore I think I need to connect a piece of wire from Terminal 15 of the ignition switch to the side terminal on the charging light. That should fix it I think as this replaces part of the loom which I removed for the indicator switch (?).


I hear entirely what you all say about the throttle. It is true, I have spare an etz clamp and tube and could use this. Though not sure an etz throttle cable would fit? More so, with the 28N1-3 carburettor there is no throttle stop on the carburettor so the cable would always be under tension and potentially have the same problems I have now. Indeed, turning the bars always tensions the cables slightly- this must be adjusted out- but that only works if the system allows slack. So, food for thought there!

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

Hallo Leute,

Also ich glaube, ich habe alle Luftlecks beseitigt (mir fehlte auch die Dichtung unter dem oberen Schieberdeckel) und den Gaszug so eingestellt, dass es einen akzeptablen Leerlauf gibt.

Ich bin sehr glücklich.
Derzeit befindet sich die Nadel in der 4. Position (von oben) und die langsamlaufende Schraube befindet sich auf 2 Umdrehungen. Dies scheint der gute Ort für das niedrigere Drehzahldrehmoment zu sein, aber auch ausreichend, dass die Drehzahl zwischen den Gängen wieder herunterfährt, anstatt zu "hängen". Aber ein Teil davon wären die Luftlecks gewesen. Also ich glaube ich habe das alles geleckt.

War gestern ohne Probleme 45 km gefahren. Jetzt sind 200 Meilen auf dem Fahrzeug, also schleppt es sich gut. Ich gewöhne mich an die Funktionsweise des Gashebels und bin damit erst einmal zufrieden. Das Bremslicht muss ich mir aber noch anschauen.

Als nächstes möchte ich mir diese Dämpfer ansehen. Die Federung ist sehr hart, und natürlich sind die hinteren Einsteller in der härtesten Position festgeklemmt... Das tut meinem Rücken nicht gut, haha

Bild für Aufmerksamkeit.

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

I have layed a new wire between + side of brake bulb, and to terminal 15 of the coil. Now the brake light lights fully with ignition on, engine off or on and doesn't dim.

Looking at the wiring diagramme that is pretty much what the standard wiring should be. But on my bike, the red+black wire that comes from + side of bulb, I do believe transforms itself into a black and yellow wire at the front of the loom. This black and yellow wire also goes to the horn. I should think that maybe the splice that was used in the factory (it all looks like factory colour wire and professional factory done too) maybe has an issue- the wire that goes to terminal 15 of the coil from the main loom is black and white interestingly. Not sure why they used different colour codes here???

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

I have since welded in a top bracket - unfortunately a bit thin, but it should hold, at least for the short term.

And also re-shaped and welded closed the broken open front seat mount.








There are a few things I would like to address. I have done 600 miles since engine re-build and whilst I have already replaced the oil, I will be doing so again in 400-500 miles and then reverting to usual interval.

- Rebuild the 4x dampers

- Check the rear wheel. It still has a pulsing when applied. The wheel itself seems to go straight- I haven't taken it off for a while. And when I got the bike both drums were rusty, so it could be the rust still needs removing (plus also removal of accumulated dust needs to be removed) or indeed maybe spokes need to be adjusted! The front was in bad condition too but has been rubbed off and that is running true and nicely.

- I need to re-build or replace the horn. I tried rebuilding it but I couldn't get it to work in my brief attempt...

- I have an issue where I can't seem to get past 65mph. I'm wondering if I need to replace the contact breakers. I have not replaced any electrical item (other than the new wire to brake light) at all on this bike. The bike runs really nicely otherwise- so possibly contact breakers jumping oddly.... the bike also bogs when in an incorrect gear, which is expected- but actually it's more like a mis-fire than simply dying. I do not have the centrifugal governer- so the timing is set to 3mm BTDC.

- I also need to think about the charging system. With lights off, charge is good at 7v, but with lights on, rarely does it get more than 6.3v. I have tested this with three other mechanical regulators and they're all the same.

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

I didn´t read every single word from you, but I understand you didn´t change the original electric system from your ES 250/2.
You could e. g. change the controller (Regler) to an electronic one like this:

https://www.guesi-motorradteile.de/inde ... 4/c/_/_/?_

Or the ignition system:

https://www.guesi-motorradteile.de/inde ... 6/c/_/_/?_ (if your generator still has the original "Fliehkraftverstellung" (don´t know the english word)).

If not, this one:

https://www.guesi-motorradteile.de/inde ... 4/c/_/_/?_

Some others replace the complete system (generator, irgnition, controller...) by a VAPE.

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Liste der großen TS

Namenlos

Jeder hat ein Recht auf eine eigene Meinung, aber niemand hat ein Recht auf eigene Fakten. (Thomas Laschyk)

Mitglied der FBF

If this happens the same way, with 3 different regulators, it might be in the generator rather than the regulator. Though 6.3V isn't worryingly low, IMO, I'd guess if it doesn't charge properly, the generator simply may not have enough power for the load of those bulbs. And then, if you do a lot of idling/low rev work, like in a city, your voltage may drop and become insufficient for a good spark. But I'd guess that doesn't happen yet at 6.3V.

Find the fault in the generator (if there is any - but this might just be as good as it gets), reducing the load (LED?) will increase the voltage, or install a new Vape set.

Btw, some 6V Vape sets also struggle to provide their rated nominal power output at low revs, but the 12V sets normally have a higher rating.

On the running issue, I understand you have the centrifugal governor ('Fliehkraftverstellung') fixated, or maybe you have another model, but is it possible there still is some radial play, allowing for inaccuracies in ignition timing?

Pulsating braking: quite possibly uneven spoke tension. Look inside the drum to see uneven wear to confirm.

Good luck!

Hi, Thanks for the replies guys.

I would prefer to keep the contact ignition for now at least unless I get specific problems. I don't think my problem is because I use points, but could be because they simply need replacing (I have them but haven't tried yet), or there are other issues besides.

For example I did 110 miles just yesterday for the local MZ club meet, and some of that is dual carriageway so I was happy to ride at 50/60mph and the bike behaved fine, but when I went on the side roads and had to stop/go slow there was apparently an ignition issue. The idle was artificially higher, and also the bike mis-fired (in an inconsistent manner). But was perfectly happy going back up to and staying at a high speed. I changed the spark plug when I got to the pub and re-started the bike immediately and all seemed well, except the same thing happened on the way home - I suppose a new spark plug was just masking the issue of (perhaps) a poor spark @ low rpm.... So... after 750 miles of use after being in a box for 40 years, we finally get electrical problems (I have had none until now except the brake light issue).

My first thought is to replace the wire, or at least just lay a new one for now between the coil and ignition switch. I don't think specifically there is coincidence that the brake light wire is shared here and I have already replaced that because I wasn't getting voltage to the bulb (I linked it to coil + to bulb +). Additionally I feel this way because the bike doesn't really like the brake light being applied. It can hickup at idle (lights on or off makes no difference).
So that's my first port of call I think, after also checking connections at the generator. For I realise on the later 12v bikes that if there is no load on the charging system then the idle artificially is raised too. This could be similar, maybe. I'll be checking the brushes there though no issue until yesteday and they are free to travel and have good length still. This wire could be integral to the general 'loping' idle I seem to get- and who knows, maybe the lack of 60+ mph too.. One thing at a time!


I have I think solved my rear wheel pulsing- I did indeed clear out the dust from it, but also applied the brake to centralise the hub in the drum before tightening it up. No more pulsing!



Puffs, no I don't have centrifugal governor so is all statically timed as TS or ETZ etc. I am reluctant to invest in such a system as vape or tezet etc. I don't specifically see them as necessary, esspecially as the bike gets little use anyway, esspecially in the dark- but more so it isn't bad enough to drain down the battery it seems anyway. I would fit a voltage gauge again but the last time I did that it was extremely innacurate, and not to mention had issues with vibration so I don't care to do that again.

Anyway, picture for anyone who is interested in a banger vs a shiner. Which interestingly in some social cultures are both the same thing. hehe

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

hi -

banger, mate, any time. way more appealing ...



best wishes, max ~:)

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http://www.alteisentreiber.de
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A shiner catches the eye more! But you keep busy polishing. A banger is for use.

But some things, like spokes, need attention after a while, and then where do you stop?

Thanks Guys,

Yes I have always been more in the 'used looking' category... Part of me cannot be bothered to upkeep the look of a nice shiny bike, but additionally if I scratch the paintwork on an already sub-par vehicle then that's not too much bother


I haven't actually been on my Trophy much (at all actually) since the 10th of April. When I got home, I tried the original spark plug in it and still had the mis-firing @ idle issue. So I left it there until a few days later I started it and it ran perfectly fine... and I had other projects to get on with...


So, The other day I put a new wire between ignition switch and coil +. The idle seemed a little healthier and what is more the charging went up to 6.7-6.8v with the lights on when the bike was being revved! So maybe the original little cable is bad, after all- it was bad to the brake light... Will have to do some testing and find out what it's like now. How it runs, but additionally if it has that problem with the mis-fire that it had on my last outting.

Still... slow progress, is progress still!

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

Right well it seems I have fixed my recent ignition issue. I was using the bike every now and then to test things, for example finding voltage drops through specific junctions of the wiring (like the fuse 'box'), but the bike would still mis-fire at idle and die and buck at low speeds.

Still, in persuit of my problems, and the fact that the bike was perfect when cold but only gradually through the ride developed problems, I decided to use the bike for work, and it was terrible. There were some severe misfiring occasions and I would have to keep the bike revving at about 4k rpm just to keep the bike from conking out at traffic lights. How very embarrasing!
As soon as I got home I swapped the condenser with one from my ETZ298cc and the ES250 was exactly the same with the misfires. And so... I used the ETZ for work for a few days and this fully ruled out the condenser it seems. Everything else checked out, stator windings, variable resistor, and even the coil measured perfect resistence readings HOT or COLD.

At one or two occasions on the way back from work the bike even failed to fire completely whilst riding.. Which made my think, this unusual and prolonged symptom development has become slowly a quite typical coil problem. I have replaced 3 or 4 coils in my time so I did wonder (but had no 6v coils spare).

And so, I bought a replacement 'MZA' (what are people's opinions on these reproductions??) coil from a friend at the local MZ club meet on the weekend, and I fitted it the other night. A quick test ride of 10 miles confirmed that it seemed perfectly happy, and indeed I rode the bike to work just to-day and no issues. I even kept the lights on, and the bike idled quite perfectly for some considerable time waiting at lights. Time will tell I suppose but it looks like this particular issue is fixed, at least..


I'm still investigating voltage drop at charge (when the lights are on) but I have yet to clean and satisfy myself that the connections at the switchgear, and the main ignition switch and the headlamp wire components are not a problem. So far, I have removed a 0.5v drop alone in simply the fuse box connection and appropriate wire terminals.. (regulator and wires to generator already cleaned). I think i've mentioned i've tried 3 other mechanical regulators which gave same outcomes. But so far this is an issue that can take the rear pew. But yes, I need to look and sand and clean and perhaps strengthen the connections. This is likely the cause.


Some more good news, I fixed my horn. I took it all apart and cleaned the contacts/points inside, and now have all electrical componants, bulbs, switches and buttons working on the ES! It isn't a particularly loud horn, but through adjustment it is the best I could get.. It's nice and loud on the bench directly connected to battery, but a little pathetic on the bike itself (even through adjustment). Oh well, at least I have one - without spending money. Perhaps with some connection cleaning in the switchgear and ignition switch can alleviate some voltage loss!

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

Forget the old 6 volt stuff. Install a 12 volt VAPE. https://www.youtube.com/watch?v=L3LCY5liwvA

Ta for the update Blurredman, and best of luck with your quest!


P-J, are you implying a 6V Vape is no good? So you believe the Vape lima voltage impacts the ignition in any way?
And as the bike runs well now, in what sense would a Vape help? Will a Vape coil still be reliable after about 50 years, and having been in a flood?

That is not remotely the point. A 12V VAPE is good in the regard that it massively improves the useability of the bike, as both 12V batteries and bulbs are cheap and available in abundance, while 6V is more of a niche market. Add to that the excellent quality of the VAPE products and the huge advantages an electronic ignition has over an interrupter one and the decision becomes quite clear. Not cheap, but worth it.

Edit: To elaborate on the useability... let's say your headlight bulb burns out for whatever reason while driving, so you stop at the next petrol station and ask for a headlight bulb (to be fair good luck finding a Bilux one at all, but Bilux or H4 is a completely different discussion). They will have an array of 12V bulbs, but no 6V, for the simple reason of it being obsolete technology.

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Well, in response to a post saying that the running problems are sorted, the VAPE Befürworter P-J advises "Install a 12 volt VAPE.". As the issue of poor running does not need to be resolved anymore, the advise given can not be for that purpose. Hence one would assume that the advise pertains to something like preventing issues like that happening in the future, suggesting something like 'with a 12 volt VAPE these issues would not have occurred'. But these problems were traced down to the ignition coil, which is close to 50 years old and has been in a flood. Hence the question "Will a Vape coil still be reliable after about 50 years, and having been in a flood?" is eminently relevant, don't you think?

Or was it maybe just a gratuitous advert for Vape?

On the matter of 6V or 12V for the generator side, there are pro's & con's for either choice. True, bulbs & batteries in 12V are more abundant, but in 6V there is ample supply too. Certainly not 'obsolete'. And for these bikes, 6 Volt is the original, and you can even find things like a power supply with an USB output to charge you phone or GPS, if so required, in 6V. Bulbs? Indeed, maybe not 'at the next petrol station' but similarly you may not find there what you need in 12V either, if it has a geriatric fitting. So take your own spares with you on a long trip. Btw, LED bulbs are available too in 6V.

Anyway, if you want a modern bike, by all means: buy a modern bike. Be aware that many aspects of our old bikes are a 'niche market', and in many ways 'obsolete technology'. If you don't want that, best not buy a 50 year old bike, buy a Zero or so.
And if you want to modernise an old bike because you don't like certain aspects of it, again: go for it! To each his own - please accept that.

Please note that on a non-MZ bike of similar age I too have a Vape set. Have had so for quite a while; it works fine, and never gave me any problems. It is in 6V, and that never gave me problems either - the bike is perfectly usable in 6V! At least for the purpose I use it for, for other things, like on a race track, it would be quite inadequate. But no bike is perfect, or optimal, for every purpose...

Whilst I agree that a total electrical replacement could solve issues, I'm not made of money, and nor do I think that is the original spirit of even MZ. For although decades old the manuals do say that:

'Repair work is a matter of confidence in several aspects:

- Finding the actual cause of the trouble; this ensures that no material is wasted and labour costs are restricted to a minimum.
- From these items results: no retouching work, short times of inoperation and low repair costs.'

It also states that although to be too 'parsimonious' in certain aspects is not advisable, I am doing this at a cost- I am not particularly parsimonious but I certainly wouldn't employ a whole electrical system at large expense just for a few little issues that can be solved through thorough investigation and a level head. Of course have driven 900 miles now and although the bike seemingly throws up an issue every now and then, I don't think I (or the bike) is doing too badly at all. But there also lies the other thing: It is not my main motorcycle. I would lothe to utilise something so expensive and barely use the machine! And, I think the original system is adequate.


Bulb replacement: Yes, the 6v bulb replacement has come up before on other forums concerning my other 6v motorcycle, but that's never concerned me. For me, if a headlamp filament blows- I will just use the other filament. If the tail light breaks in the night, I will swap the wires so that the brake light is always illuminated. If the brake light fails during the day, the reverse will be done (if I had indicators, I would take a bulb out of one of these). And replace bulbs in time when convenient. On a long trip I carry specific spare bulbs, but not for commuting to work. I do this with the car.. If my car has 4 brake light bulbs (each with two filaments in for tail + brake), I would not carry a spare. For if the indicator bulb blows (which also acts as a pilot lamp), you could use the bulb from the brake light. No messing around. But 6v bulbs at a petrol station aside, I'm not specifically sure you'd find the p45t fixing or specificly sized festoon bulbs either, as you say.

My battery was relatively cheap (cheapest I could find) and easy to get (I buy most of my stuff on-line these days), and certainly bulbs are cheap on-line too. And if you're ever stuck for a 6v specific bulb you can just purchase a 12v bulb with half the wattage, this will give you an equal outcome.


Ultimately, I don't think there's a problem with the 6v system on this bike (or any bike). Just some headscratching and investigation is required. I post only to this topic as an interest to other people who might also be in the same situation. It might seem like I am looking for help, but it is indeed you could say a hobby to be investigating such things and documenting them for other people who need help and discover the topic.

I'm quite a fan of the original MZ systems. They are adequate (and in the case of the 12v generator very generous). Little black boxes of magic can break sometimes! But a contact breaker ignition can be fixed in difficult road side conditions!

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles

If you convert then to 12 volts. Just to get better light. In addition, you can get parts in 12 volts everywhere. I've been driving the 12 volt VAPE in my ES250/2 since 2001.

Better light? I have 2 bikes at 6V (both CDI), one has a 50W incandescent headlight, the other a 55W halogen. Plenty of light & visibility! And I rarely need parts, and if I do, they're easy to get...
Excellent trip today in the sunshine, 100+km in the beautiful area here. Always ride with lights one (mandatory, + I want to be seen), but don't ride in the dark anymore.

Yes Blurredman, you are right, re-building the entire wire loom & switch gear (which is not part of any Vape / Turbo-Zabitsky or the like set) is both quite intense as well as costly. And by the sound of it, you're pretty much there. Bulb-wise there's always more than 1 way to skin a cat. Horn a bit hoarse - ah well, such is life.

My ETZ is still on (original) points, for more than 60k km now. No probs. Yes, 12V H4, used for commuting in the past (very often in the dark), and that might be better. Not required now.

Es250/2 and etz 250, both vape and 90/90 h4 Light.

Uh... No? You need a 12v bulb with four times the wattage. So to get the same illumination as a 20W 6V bulb you need an 80W 12V bulb. And even then it won't work because the electrics of the bike would just die at the mere sight of the 80W bulb. Light level and output is directly tied to resistance, which is why running a 12V bulb on 6V is nonsense even if you scale it correctly

_________________

Hi,

Feel free to read this interesting article about how to optimize a 6V electric system:

https://pic.mz-forum.com/lothar/ELEKTRIK/ES-Baum.pdf

Another articles, that are, in my opinion, worth to read, can be found here:

Kraftfahrzeugtechnik, 6/1987, https://pic.mz-forum.com/harald/HomePage/198706_KFT.htm

http://www.simantik.de/mz-scheinwerfer-licht.shtml

Oh but P-J, why stop at 90W? https://www.amazon.com/HELLA-H4-130-90W ... UB4CW?th=1 !

The issue is: I do not need more. Why would I? I've found a standard (55/60W) H4 quite sufficient on the darkest country roads, while nowadays I only ride in daylight (preferably sunshine!).
True, for something like 24H races in the EWC (where the speeds are slightly more than a standard 250cc MZ achieves, so that you need to look farther ahead), or offroad riding at night, it will be useful. But not for bikes like this, and it would certainly not be the highest priority modification I'd choose. As said, I consider my lights, also on my 6V bikes, entirely adequate.

Some more questions/comments on these over-standard Wattage bulbs:
- Is it really a good choice to blind the oncoming traffic with such intense light?
- If you're going to dissipate double the power the headlight is designed for, will there be thermal issues? Ventilation?
- If you use LED you need maybe as low as 10% of the power to achieve the same light output, consequently these high Wattages seem not required (regardless of how much light you think you need). Now there's a thought: 130W in LEDs...!
- Thinking of photon drives as considered for interstellar travel, it might be a better idea to fit that headlight at the tail.

samyb, thanks for those links! Especially Lothars documents are very useful and much appreciated.
But Gaston Lagaffe doesn't have lights at all there...!

I beg to disagree:

Clic

True, sometimes he has: just not in your profile pic...

Hi,

Been a while- but since May have done 2,500 miles. I do not commute on the bike though any more because of my work life has changed and thus the miles will not increase anywhere near as they used to.

But i've done a bit on the bike, in amongst my other projects which have taken some of my time too (including my ETZ 250 w/ 298cc (piston ring broke and took piston with it), and my ETZ251 (clutch slips and stalls at idle (seems to be electrical as runs nicely otherwise- been a long term problem)), and welding work I've been putting off on my car.

In the past few months on the ES specifically I have:

-Changed hand grips,
-Cleaned up the ignition switch connectors and wire terminals to remove some voltage loss (bike charges better now with lights on- I'm happy with where it stands here and I'm not going to look into it anymore),
-I have repaired the horn by disasembling and cleaning connections,
-I put on a new coil (this solved my small electrical issues (stalling at lights) which progressed into extreme problems with running over time - it was just more noticable with lights on), the coil that came with the bike was not original (dated '77 instead of '72) anyway, so may have been a problem in the past already or someone leaving the key on,
-I've done various maintenance things obviously like cleaning the brakes (though has started squeeking lately- plenty of life on shoes and all of the shoe is making contact) and adjusting/lubricating chain. Additionally, changing the oil after initial running in period after rebuilding gearbox, there is still some warp in the rear brake drum. But it's not too bad and i've lived with it until now.
-I have fitted a mirror onto the bike by lathing my own adapter to take the place of the brake lever pivot bolt so now I can see safely behind me,
-I have lowered the main needle (to middle, default position) as it seems it was running a bit rich and this is part of the problem to the bike 'bogging' at low RPM, high gear applications. It might still be running rich as the tip of the needle looks a little damaged to me, but I need to get a new one.
-Rewelded the seat support bracket as my previous one had failed.


There are a few things which need attention still.

-I have recently realised the holding bracket for the headlamp lens was broken after a ride when I saw the lens almost falling out the front - I have yet to fit the replacement I have,
-The rear suspension is too tough for my liking, and all four have likely never been rebuilt anyway. But the adjusters are of course typically seized. That requires some heat and time and patience. I don't have two of those..
-I still have yet to even install the replacement chain gaiters, it's just a messy job I keep putting off.
-I have yet to caustic soda the exhaust - I took the rear apart off recently and it was quite carbony for only 15,000 miles. Perhaps some old owners used straight motor oil sometimes.
-The speedo, which whilst accurate within a couple of MPH initially after re-building, after a period of time, esspecially noticed after coming back from a camping holiday on the bike, now reads 10mph too fast! It is interestingly consistent in the range and doesn't wander, it just means I need to do '40 mph' according to the clocks to actually ride at 30mph. And as I say, consistent that if I want to do a real 60mph, I must do 70mph according to the clocks. The mileage counter drum itself ticks nicely over the miles and accurately! I have yet to take it apart again, but it's intruiging... Ideas? (cable is new).

I am very pleased with the MPG of the bike, it is by far the most economical vehicle I have and despite reading and not initially believing the 60Miles per gallon vs 75miles per gallon difference between ETZ and ES, I am very happy with the outcome. It has given me some savings in the last few months which is handy in the time of excessive fuel price, not to mention I am the only one who earns money in the household- these last few months have been extreme. https://www.fuelly.com/driver/blurredman

_________________
1973 MZ ES250/2 - 18,000 miles
1979 Suzuki TS185ER - 10,000 miles
1981 Honda CX500B - 91,000 miles
1987 MZ ETZ300 - 40,000 miles
1989 MZ ETZ251 - 51,000 miles