Installation of Lichtmaschine from Ulis Motorradladen? R25/3

Begonnen von FelixM, 08 August 2021, 20:56:06

« vorheriges - nächstes »

0 Mitglieder und 1 Gast betrachten dieses Thema.

FelixM

Hello!

Just spent nearly 500 EUR on a brand new Lichtmaschine and the damn thing doesnt fit (to small holes) with the original screws...(the two connecting the breaker point) Right now I'm a bit fed up with completely unnescessary problems and disappointed...

No information is available about other dimensions than original. Still the unit apparently lack the precision needed for straightforward installation.

Anyone with experience of the thing? Did you ask for a correctly manufactured unit or did you change the screws? Did you make new threads? Shouldnt be nesscessary when you spend that kind of money... :schluck:

FelixM



Freude

this seems to be absoluty correctly manufactured  - as the orginal screws are d 3,5mm - your "inbus" type ones are m4 !

FelixM

#2
Zitat von: Freude am 08 August 2021, 21:14:02
this seems to be absoluty correctly manufactured  - as the orginal screws are d 3,5mm - your "inbus" type ones are m4 !

Ok, but what could the reason be that they wont fit in the new unit, they seem to chew away the metal and never catch the threads?

As you see in the picture below they fit perfectly in the old unit.

Eppo

#3
Maybe the old ones were worn out and were replaced by M4 screws, it looks so as to me I don't know if there exist M3.5 with this style of Allen key head.
Has you a measuring gauge? M3.5 boreholes has 2.9mm while M4 boreholes has 3.3mm.
another way is to check the screws/thread with some reverences that you are familiar with, like test the screw if it fit to a M3.5/M4 nut or otherwise the thread with a screw M3.5/M4 that you are familiar with.
Geht nicht, gibt's nicht. Einfach kann ja jeder 😁.

FelixM

Zitat von: Eppo am 08 August 2021, 22:19:03
Maybe the old ones were worn out and were replaced by M4 screws, it looks so as to me I don't know if there exist M3.5 with this style of Allen key head.
Has you a measuring gauge? M3.5 boreholes has 2.9mm while M4 boreholes has 3.3mm.
another way is to check the screws/thread with some reverences that you are familiar with, like test the screw if it fit to a M3.5/M4 nut or otherwise the thread with a screw M3.5/M4 that you are familiar with.

Thank You.  I will check measuments tomorrow. I either case the easiest solution would be to get a smaller screw.
I don't think they have been replaced- they fit perfectly in the original Lichtmaschine.

4Taktix

Hi Felix,
you should urgently check the length of whatever screws you mount finally.
They must not touch the collector of the rotor by no means. ( directly behind the holes )
Otherwise this will destroy your dynamo in no time. ( short circuit )

Regards,
Sascha
Think outside the box !

Krottenkopp

#6
The head of the original screw was a slotted one.
An allan key screw makes it a little bit easier to check the breaker point.
Take a look in a shop for RC Models, the 3.5mm screws are often used to mount the electric motors of the models.
The original length was 5mm (this is measured without head)






Gruß Heiko/2
Gruß Heiko/2

FelixM

Thanks a lot for input! It most likely is so that my "original" actually has been tampered with (new threads and allen-screws) My garage buddy said he had some that could fit. Will check later.

Another thing: there is now a gap between the new Lichtmaschine and the crank case. I believe the rotor needs to be screwed in to fit (using the original bolt) before the rest can fit.
As you mentioned Sascha, there mustnt be any connection between the base of the breaker "holder" on the Lichtmaschine and the rotor.

FelixM

Waiting for correct screws I tried to make sure the Lichtmaschine fits correctly to the crank case. There is a pretty large gap between them and it doesnt seem to change when I tighten the three allen screws.
To make sure the rotor was tight I tightened the bolt but now I cant remove the new Fliehkraftregler! The old one just fell of easy (of course, due to use). Any ideas? Just pull and wiggle? Guess its unwise to use any tool in order to not damage the rotor or other components...

FelixM

Did tighten the allen screws (according to markings inside "BMW" - the Lichtmaschine apparently has holes made for other bikes ) and now theres no gap.

But now I noticed scratches on the rotor! It seems the damn thing is uneven on the inside of the baseplate for the breaker! WTF!! Fortunately the battery is not connected but again, what s#@!t is going on...I guess I have to remove it and file it down. Could have been done at the factory one might think...

FelixM

Here is the culprit! Unfortunately bad focus but the metal is at least 1,5 mm above the surface and touches the rotor. If it was some china crap from alibaba for 50 EUR I wouldn't be so p....ed off, but I expected more.

FelixM

Here is the thing from the side. It could be that it is that lenght on purpose to fix the screw  - but then the rotor must go deeper! I guess I should not use a hammer or anything like it but how do you know when the rotor is at the bottom?

Krottenkopp

Are you sure that the groove of the rotor is correctly placed?


Gruß Heiko/2
Gruß Heiko/2

FelixM

It goes seemingly deeper than if it was outside the groove. If theres room left it could be a mm or 2. But for not touching the breaker plate that would be enough.

Heres a pic of the old Lichtmaschine and the new. Note the small gap. When the allen screws to the crank case will be tightended the gap will be ever smaller...

Should I get the hammer and just tap...?

FelixM

Hmm, seems that the rotor must go deeper. With the unit attached to the crankcase there is contact between rotor and baseplate....

Sch...e!!

FelixM

Ok, removed the rotor (which of course was seated in the groove) and compared with the original.
Excuse my language but how the f!@#%k it the new rotor supposed to fit? It was "only" around 350 EUR.

Close to sell off this !@$$& and buy a modern bike... :schimpf:

Jürgen 57

Hi Felix,
the old rotor looks quite ok. Is it defect? If it is not defect / broken, why replace it with a new one (?).
Just send Uli your infos and ask for a replacement and/or return if the old rotor is still ok.
And: don't give up! ;D

Rgds Jürgen

FelixM

Hi Jürgen,
Thank you for the support. I need it...Right now in a mood where it seems Murphys law rules the universe- or at least vintage motorbikes...
But still - one could expect that spare parts, very expensive spare parts, were "bolt on". It says "BMW R25/3" and naively the customer assumes everything is ok and fits. I realize details can sometimes differ between manufacturing years on all motor vehichles,  but that is something a professional spare parts provider should be aware of.

Unfortunately the groove for the Fliehkraftregler on the shaft of the original one is damaged.

mekgyver

#18
Hi Felix,
try to give this scrap back to UliS to get your money back ! All the scrap ! All those things are unfortuatlly not optimal.
What a shame on this company ! I think meanwhile Uli himself is not leading this comp.
Good luck, mek  :schrauber:
... 73er-Gang

rolf

#19
The groove for the Fliehkraftregler is nothing to worry......it is for make it easier to fix him after get him off..it is NOT for fixing the postion if the engine is running....therefore is the M8 screw.....if there is no or a wider groove.....you only have to put the FKR and turn it to where you want....here: the ignition-point ;D

Taz

Hello Felix.

Maybe you want to check the number embossed on the generator rotor with the data provided in our comparison table we are keeping around for exactly this kind of questions....mechanically the one you had received doesn't seem to fit, maybe you can corroborate this impression with the model number of the rotor...

https://www.bmw-einzylinder.de/Vergleichstabelle/default.html#lima_EN

Kind regards, Taz
Ich hab noch nie einen Sarkasmus vorgetäuscht


auf Tour:

Zipfelreise (2019)
Cymru "Radnor Revivals" (2016)
Alba "Isle of Skye" (2013)
Austria Großglocknerhochalpenstrasse (2012)
Alba "Spittal of Glenshee" (2011)

FelixM

Hi again! Been working on my oldtimer Alfa and it passed TÜV/MOT!

Anyway: I got a new rotor from Uli's (Thank you! Excellent service in sorting out the problem) which fit (there are apparently variants - beware!)

So, I attached everything according to available sources  - and - no! The thing wont start. Theres no spark from the sparkplug. Well, I'm not surprised. I just felt "But of course!!)

My garage buddy will have a look with the multimeter later today, hopefully...

But from the pictures or otherwise  - do you have an idea?
(The red cable from the battery has a damage in the plastic cover, therefore the tape)
One thing I'm unsure about is the "meeting " of the cables from the ignition coil and condensor - the little orange lastic isolators/washers are they placed correctly?? Not sure about their purpose...

Borgward


FelixM

#23
Zitat von: Borgward am 18 August 2021, 12:17:06
do you have the third little washer between the two others?

ref. to:
https://bmw-einzylinder.de/forum/index.php?topic=15485.msg213002#msg213002

Hubi

Hi !

That was exactly the kind of schematic illustration I was looking for, thank you!
Will have a look. I  believe I have these..

rolf

the "meeting" is correct
measure the Unterbrecher....0 Ohm when closed.....and "unendlich" Ohm when opened?

FelixM

Zitat von: rolf am 18 August 2021, 13:29:22
the "meeting" is correct
measure the Unterbrecher....0 Ohm when closed.....and "unendlich" Ohm when opened?

Ok, thanks! Excuse a newbie - exactly between which points should I check the resistance? When closed there is a gap right, so how can it be 0?

mz-henni

There should NOT be a gap between the breaker points if closed.

Greetings, Hendrik

rolf

#27
CLOSED WITH A GAP IS NOT CLOSED ;D

so you has the reason why the ignition doesn´t work...it MUST closed ( and opened)

Krottenkopp

Gruß Heiko/2

Kurt in S.A.

Kurt in S.A.

Similar topics (5)

Hauptmenü

Anleitungen & Bücher Baureihe Specials Startseite Vergleichsliste

Presse & Wissen

Bauzeiten & Stückzahlen Historisches Liste der BMW Modelle Presseberichte Prospekte & Plakate

Foren & Literatur

Bildergalerie Bildtafel-Suche Forum: Boxerforum Handbücher Servicedaten

Allgemeine Infos

Bildtafelsuche Glossar Impressum Kontakt Sitemap

Tipps & Service

Dienstleister Händler Märkte & Museen Tipps Verschleißteile & Werkzeuge