Author Archives: Chris Williams

E10 unleaded petrol – can we use it?

Hi everyone,
Is there any technical information available for the use of the new fuel in MZ motorcycles. I haven’t been able to find anything to say yes or no. I’ve recently topped up the petrol tank in my 1990 MZ 251 ETZ with it in but not sure if it will damage it or if it’s safe for regular or occasional filling.
Kind regards,

Exhaust leak at clamp joint on ETZ 251 and front wheel bind

Hi everyone,

Looking for answers to the two small issues pre taking restored motorcycle to its first MOT for 16 years!
On tick over and a little light revving in the shed I have noticed a dribble of oiliness coming from under the clamp holding the down pipe and silencer together. I have tightened the clamp up and it has diminished but still drips a bit. Is there supposed to be a gasket there as I can’t seem to find reference to one other than possibly an ‘exhaust elbow gasket’ but no clue as to where or how to fit it and the shape seems wrong!
The other issue is a slight bind on the brake pads which happens for about a quarter of the front wheel turn. It doesn’t stop the wheel turn and I think the disc is true and the wheel looks true and I’m not personally overconcerned but I want it to pass the MOT! grateful for any help. Kind regards, Chris

Tax and MOT for restored motorcycle

Hi fellow MZ riders,

I’ve just restored my MZ251 ETZ solo m/cycle. It has been SORN since 2006 although DVLC ceased sending me SORN declaration demands after 2013. I now wish to get it back on the road, particularly as I’ve invested a great deal in getting it back into a good condition and want to remind myself of the pleasure of riding it! Do I need to notify DVLC before I seek to insure it and have it MOT’d as I won’t be able to get it taxed beforehand. Anyone with recent experience of this?

Kind regards to all fellow restorers and MZ lovers.


Dismantling generator on ETZ251 – how to undo rotor?

Hi everyone,

I’ve acquired a Tezet electronic ignition kit to replace the points system on my 1990 ETZ 251. Trouble is the Haynes Manual does not describe or show how to remove the existing generator from the engine. Allen key on central bolt merely turns the engine over like the kick start. Do I need a special tool to remove the generator? Thanks in advance for any help with this

Help needed Oil pump on MZ251 air lock near crankcase

Hi everyone,

I am trying to get my 1990 MZ 251 back on the road after 16 years in the shed! I have just changed the feed pipe from the 2 stroke oil container to the oil pump and I am happy that this has no air lock as I have now bled it. However, the small pipe from the pump to the crankcase has also been replaced by me but a few air bubbles remain after filling it with oil and reconnecting to pump and crankcase spigots, and I cannot work out how to further bleed this pipe – will the pump push out these air bubbles (air locks?) when I eventually get the engine started, or do I need somehow to remove them beforehand, and if so, how, as the pump will not work without the engine running, if I have understood its mechanism correctly? Any answers to be gladly received.

Carburettor priming

Can anyone tell me whether, after reconditioning the carb on my MZ251, I need to prime it first before refitting. Unfortunately I have refitted it without doing so! Fuel is flowing from the petrol tank to the inlet of the carb but none seems to be reaching the spark plug

Decarbonising exhaust on ETZ 251

Hi everyone,

When using caustic soda to clean out carbon on the long exhaust pipe, which end is bunged up?The manual is ambiguous on this and I had assumed the end of the exhaust containing the baffle would be bunged up and solution put in the other end. Any advice on the correct procedure would be appreciated.

New member – restoring MZ251

Hello, I’ve just joined as I am in the process of restoring my 1990 MZ251 and, although I can see the project end in sight, I may need some additional guidance for completing the rebuild correctly. I am pondering over adding electronic ignition and changing the carburettor but will hold off until I know it fires up with the points ignition. A current conundrum is the rear brake mechanism – I have got it working but only with the cam lever upwards, as otherwise it fouls the side stand – any ideas if this is legal or sensible?