Got the MZ ts125 home now won't start

[Saffrican]

Went to pick up the bike on Sunday and the owner bike started first kick. The engine was cold and according to the owner, had stood for a while. I rode the bike up and down the road, it accelerated briskly ( as only a 40 year old 125 can ) and shifted rhrough the gears easily and smoked very slightly.
Parted with the hard earned shekels and brought the bike home.
Went across the road to the parking lot and drove it around with my excited son for about an hour. Started easily and all seemed okay.
On Monday after work my son wanted to have another go and nothing. The bike refuses to start at all. I drained the tank, put fresh 30:1 in, changed the plug, drained the float bowl. Nada. Nothing.
There is compression, spark at the plug when I earth it and the plug is wet when I take it out after half a million kicks. There is fuel coming out of the tap and the float bowl has fuel in it.
At this rate I am going to have one giant kick starting leg.
Can anyone help?
I cannot work out why it suddenly stopped. The battery needed a charge and top up. Condenser or something so obvious I cannot see it. Wiring all ok but I did notice the fuse had blown. Replaced it and half a zillion kicks later I am starting to lose it. Big time.
Help!

[DAVID THOMPSON]

your suffering from the reason i stopped buying 2 strokes about 1969
dave

[Blurredman]

Double check the spark plug is the correct type. A lot of these smaller bikes have improper spark plugs.

When I first got my ETZ250 it came with a B8 which worked after subsequent use of it for weeks, but one day it just didn't work anymore. I bought a correct grade of spark plug (slightly hotter B7) and it always worked since, at least ignition wise in that capacity.

Also, double check the voltage on the 6v battery. MZ's need a good charged battery as the engine is not self exciting like a lot of kick start bikes are. The spark is DC and taken from the battery provided by the alternator, the same as a car. Lots of older bikes with kickstarts use AC to power the ignition system.


There's little point draining the fuel, it doesn't age until at least a few months and i've used the same fuel that has been in bikes in my own storage started every now and then for up to two years without issues concerning fuel.

Also, when starting the bike, don't turn the lights on too! That takes energy from the battery that is needed at the spark, and if the battery is a little low it can make a difference!

Also, double check the 'choke' is operating properly with the rubber plug that fits into the small slider is present and not making the bike run too rich when you're attempting to start it. And whilst on the subject there is a lot of talk about 'starting technique of an mz' as i'm pretty sure the previous owner might have tried to teach you. It's a myth really, all it does is prime the engine.

All you need to do is turn the ignition on, pull the 'choke' kick maybe once or twice with it engaged and then subsequent kicks should require no choke at all.

Internesting note aside, If I park my bike up for the night or in the day for a considerable time (like getting to work and not using the bike for 8 hours), I use the choke to turn the engine off. This acts as flooding the engine, but also allows me to start the bike typically on the first kick the next use.

Also, don't pull the throttle whilst kicking the bike over. Just use the choke for the initial couple of kicks.

You may also want to double check the carburettor settings with the manual stated for the carbruettor. Bear in mind that these are just base standards when the carbruettor is new and might need to be changed after, so take note of what yours are at current so you can compare how far off it is, if it is indeed off.


Clean off the plug, by burning off the petrol by igniting it with a lighter or something, and try the above, including double checking the battery voltage. It's a possibility that it might not be being charged either. Take note that the battery is not charged at idle and may even discharge slightly if you have lights/indicators on etc.

[Saffrican]

Thanks Burredman. Lots to think about and do.
I notice that the key in the headlight seems to have quite a few settings to the left and right. Is this by design as the headlight stays on when the orange light on the speedo goes on which I assume indicates the electrics are on. I cannot see where to switch the lights off as the rudimentary controls only allow bright and dim beam on the right handlebar.
I do suspect the battery might be the culprit and will check the voltage. I bought B8HS plugs which you say are wrong so must I get a B7HS?
Thank you again for the help, most appretiated

[Blurredman]

I'm not sure what specific plug it should have, as my documentation is mainly focused around ETZ models, which do require the B7HS.

It's quite likely that your little TS is indeed a B8HS, but it's worthwhile looking at manuals. I don't have the TS125 Haynes, only the ETZ. I'm sure someone else on this forum can provide, and I can then also mirror the data on my own server to provide myself when required by someone.

I haven't got first hand knowledge of the TS, but I the clocks have two lamps in them which give tell tales for 4 particular jobs. I am unsure which is which, but I believe that one of the lights is a neutral indicator, but when you turn on the indicators it flahes, whether or not you are in neutral, I believe it also stays on when the bike is discharging from the battery beyond the ability where it could reasonably sustain the engine, but that could also be the dual job of the high beam indicator if said bike has one. I'm not too sure. Regardless, I double checked and I do have an official service manual located here in PDF format, which includes all you need to know even about the ignition switch (but unfortunately it states an IFA specific spark plug not an NGK equivilent):


ftp://blurredmanswebsite.ddns.net/Vehic ... Manual.pdf

It also has better detailed information as to what idiot lights do what and how, instead of my guessing above.


The key in the lamp is also the lamp switch. In the default position of being off, the key enters the lock in the position of around 5 o' clock.
Ingition on (with no lights) is acquired when flicking the key clockwise to 6 o' clock, the next position over at 7 is side lamps, and the last position 8 is main beam, where as you have found out you can control whether the main beam is dipped or not at the switch on the handlebar. Also to note, the side lamps (or parking lamps also known as) are at the 4 o clock position. You cannot /should not be able to take the key out of any position other than 4 and 5.

If the lights are left on with the engine not running it does not take very long at all for the battery to go flat at all, as the main beam is actually very powerful and the coil will also be receiving current which is unspent, which is also dangerous for the coil as it can burn out. This is why cars have accessory slots for radios.