MZ/MuZ Riders

Hello all,

First of I'm a new owner of a 1986 MZ TS 125 Luxus and an even newer member to this forum!

I've had the bike for a little over two months now and got a good amount of solid riding out of it however last week it began to die shortly after starting it up. It had been running a little hot for some time prior to that but I didn't imagine that it was a big problem however about two days before it became inoperable the engine also began to misfire resulting in a very jumpy commute home.

To attempt to fix it I've replenishes the air filter, checked the carburettor, replaced the battery, changed the gear box oil, put new spark plugs in (B7HS) and also cleaned of the 30 odd years of grit coating the engine fins. Sadly this is all to no avail and it still repeats the same process of starting, revving and then dying.

If anyone has any helpful hints of suggestions it would be greatly appreciated as I am running out of ideas!

Many thanks,

Any knocking, or metal on metal sounds? What is the spark plug colour?

Also.. Do you know that the bike is charging? When the battery is low, these bikes behave a bit bunny rabbit-ish - I should know. Been there done that, more than once unfortunately.

Thank you all so much for the replies and the warm welcome!

There is indeed the sound of mental hitting against mental coming from the cylinder and as for the spark plug (after some riding) it is coloured by a black lair of suit. Could this perhaps be due to carbonisation and if so how would I go about correcting this? The battery appears to be charging alright, have taken it out for a spin when it was low on power and by the time I came back it was at a lot healthier a level of charge.

When I was checking over the carb i did give the jets a wee inspection an they all appeared to be clear and clean... the carb was overall in remarkable good condition so I hope I haven't buggered it in checking over it. I'll need to have look at the ignition timing / contact breakers as I have not really investigated them so far.

thanks so much for all help so far, I would be lost without the help!

L_Greer wrote:There is indeed the sound of mental hitting against mental coming from the cylinder

Oh dear.. If you can hear metal on metal, even when just turning the engine over by hand, slowly. This is not a good sign- You really aught to take the barrel off and check. It is a possibility of many things that have occured. The piston may have snapped a ring, the piston might be badly scored. Or the big or small end could have collapsed.


It's not hard.. Infact on a ts125 i don't think you need to do anything other than take the exhaust off to get the barrel up?