ETZ 251 charging at above idle

[tonyc]

When my ETZ idles the battery charge light is out. If I rev the engine, it comes on. The battery will discharge after a run of 30 miles (its a new one) resulting in my having to walk home! Any ideas?

[radiograf]

See if this link will help http://www.sweller.co.uk/mz/electrics/alt_chgelit.html

[DAVID THOMPSON]

in some systems the size and type of charge lamp needs to be correct
or it can cause you problems
the wrong bulb can mess things up..
this may not apply to MZ but it does to some systems
dave

[radiograf]

Definatly sounds like your voltage regulator has gone. Time to change it for an electonic one. Instuctions to do this here, http://www.sweller.co.uk/mz/mods/mod_12vreg.html or purchase a 5 connection one off german ebay.

[Norman Wade]

Before buying anything, it might be worth checking the length of the alternator brushes. (Can someone check the manual and let us know what the length should be?)
I remember when my brushes got a bit worn the charge light would come on at high revs. The more they wore, the lower the revs the light came on at.

Norman

[tonyc]

Thanks for all of your suggestions. I have just taken the brushes off and one is longer than the other. The shortest has 8mm sticking out from the holder at the highest point of the brush's ark. The book said that they need to be at least 9mm long, but I don't know if that was the total length or the length sticking out of the holder. one seems to be dragging, because the contact face was not worn to an arc, it was worn more like this;

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rather than this;
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[Norman Wade]

It's a long time since I owned an ETZ, but you should be able to remove the brushes from the holder. Compare them with the one in this photo to see if they need replaced. http://www.mz-b.net/index.php?page=shop.product_details&flypage=flypage-ask.tpl&product_id=700&option=com_virtuemart&Itemid=87
As you can see, they're fairly cheap, and there are probably other suppliers.


Norman

[radiograf]

On ebay now http://www.ebay.co.uk/itm/MZ-ETZ-DYNAMO-BRUSH-AND-SPRING-KIT-/280796146810?pt=UK_Motorcycle_Parts&hash=item4160c12c7a

[therealche]

On ebay now http://www.ebay.co.uk/itm/MZ-ETZ-DYNAMO-BRUSH-AND-SPRING-KIT-/280796146810?pt=UK_Motorcycle_Parts&hash=item4160c12c7a

Thats one hell of a mark up! I could probably get then sent from ost2rad for that price, thats including the €11 P&P!

[tonyc]

Yes parts from the UK seem impressively expensive! Where are MZ parts made? I realise that the brush is probably common to more than one bike and so could come from a variety of places, but where are the other parts like brake disks etc made? If the production line machinery to make them were sent to Turkey when MZ sent 2 stroke production there, are the British and German parts shops not buying them from the same place, namely what is left of Turkish production facilities? If they are then we are being robbed blind by British suppliers.

[Trogolodyte]

os2rad,com price rotor brushes as 3.95 euro's or less each depending on the length of the brush required

+11 for postage = a max of 18.90 euros... or £15.22 ish

[tonyc]

I changed the brushes and springs and the fault is still the same. What should the voltages be across the regulator?

[tonyc]

The regulator and the brushes have been changed. It is still not charging at high revs. I recently changed the ignition barrel. Is there anything that I need to check in there or the headlight that is part of the charging circuit that I may have damaged?

[arry_b]

Check that all of the wires that go down to the dynamo have continuity. I've see this happen when one of the wires had an internal break - the one to connector 61 as I remember.

No excitation current = no dynamo output.

[tonyc]

The wires were fine. There was a bad connection on the regulator. The one that is hard to reach! Thanks for all your help. I now get 15v when revving and 10v idling.