I had some weird electrical issues I tracked down to the alternator not working.
I used my trusty Haynes workshop manual to work see how to change the regulator and bushes. It is easy but getting a replacement was not so easy. When you give suppliers the part number on the regulator they shake their heads, when you tell them it is for your 30 year old K bike they just about piss themselves laughing!
Anyway Bosch part #1197311090 fits & works & replaces #1197311001 and my local supplier had one on the shelf.

Did you try ebay?

yep hard to find someone serious bigsax .....but the regulator is pretty common ...as you found ... always best to tell them that its a 30 amp bosch unit ...   don't mention its from a bike though ...just say its out of a vw

id be interested to see what your voltages are after it has charged the battery fully ....be aware that there are what they call the "city type" regulators ...made to charge at about 14.2 (reason being that short runs all the time ) and the "country type" which sit about 13.8

just so you are aware ....the 14.2 burn off the electrolyte pretty quick ...so 6 monthly refils are recommended .

charlie99 wrote:yep hard to find someone serious bigsax .....but the regulator is pretty common ...as you found ... always best to tell them that its a 30 amp bosch unit ...   don't mention its from a bike though ...just say its out of a vw

id be interested to see what your voltages are after it has charged the battery fully ....be aware that there are what they call the "city type" regulators ...made to charge at about 14.2 (reason being that short runs all the time ) and the "country type" which sit about 13.8

just so you are aware ....the 14.2 burn off the electrolyte pretty quick ...so 6 monthly refils are recommended .

Getting 13.8.

STILL NOT FIXED MY PROBLEM GRRRR.

Just been out for a run and the battery ran flat & electrics started playing up again. What am I missing?

where are you measuring ? at the battery terminals ?

ricks post a couple of days ago about the alternator earths etc is well advised

is the charge indicator lamp operational ?

is the under tank earths all good ?

is the main earth cable corroded - lossy ...many have replaced theirs totally

alby did a small kit for the main earth wire ...increased it by nearly double

he may still have a couple

or it is just a dud battery now ?

Checking current at the battery terminals. Something strange though, the current does not charge at idle, it only picks up at about 2500 revs. The battery charging indicator light stays on initially but goes out as soon as 2500 is reached and stays out. The main battery earth lead is good as new, I have not looked at the others yet.

2500 that's a little high    normally about 1200-1500 is when the lamp extinguishes


how are the money nuts (in the coupling between the motor and front of the alternator )

did you inspect the slip rings (copper bits that the brushes run on ) around the armature of the alternator

they should be clean and shiney if not get a bit of scotch bright and make it so ...
I have seen those rings stuffed from bad brushes becoming too short and driving into the slip rings at an angle ...but usually they just don't reach any more with age .

unless you have cracked a brush during the installation ....I usually hold them back with fishing line whilst working them into the right location ...just before doing the bolts up \
\

charlie99 wrote:2500 that's a little high    normally about 1200-1500 is when the lamp extinguishes


how are the money nuts (in the coupling between the motor and front of the alternator )

did you inspect the slip rings (copper bits that the brushes run on ) around the armature of the alternator

they should be clean and shiney if not get a bit of scotch bright and make it so ...
I have seen those rings stuffed from bad brushes becoming too short and driving into the slip rings at an angle ...but usually they just don't reach any more with age .

unless you have cracked a brush during the installation ....I usually hold them back with fishing line whilst working them into the right location ...just before doing the bolts up \
\

Thanks Charlie, I will try cleaning up the slip rings, they did look a bit sooty and the old bushes were really short. 
I am off to do it now and will report on results..

good luck mate

No good, now no charge from the alternator at all! And the starter is now playing up. When it rains it pours!
Looks like an alternator rebuild.

better post up a pic of what you see ...did the terminals go back on and clean from the wiring harness , how did you turn the alternator to get to all the slip rings ...that was mighty quick unless you used the motor to turn it ?


you didn't pop a fuse in the process ?

Most likely the starter is giving static because the battery is low.  Charge the battery and take the alternator to a auto lecky and get an opinion.

charlie99 wrote:better post up a pic of what you see ...did the terminals go back on and clean from the wiring harness , how did you turn the alternator to get to all the slip rings ...that was mighty quick unless you used the motor to turn it ?


you didn't pop a fuse in the process ?

Yep, used the starter motor (now giving me trouble) to turn it. And cleaned the terminals. I can now strip the battery etc out in times that would impress formula one teams.

I even tried putting the battery charger on when she was running to see if the boosted charge would turn off the instrument warning light. No.

Anyway, so now the starter is playing up and I decided to remove it. I have so far sheered the head off one of the retaining bolts!

I am now typing this with a philosophical glass of red in one hand and the remains of the bottle not out of reach.

um settle on that for the night

do not go out there again ....till tomorrow is well and truly dawned ...

grin

things often look differently in the new day

It's possible that you may have a bad diode in the alternator.  The diodes are not part of the regulator.