BMW K bikes (Bricks)

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1Back to top Go down   Electrical Problems Empty Electrical Problems Wed May 30, 2012 2:28 am

Tom GR

Tom GR
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G'day All, it's been a while since a post so here goes.The K75 started spot on,idled about a half minute then cut out.The ignition lights dimmed but the headlight stayed on nice and bright.Then,when ignition is turned off and on again,ignition lights are as per normal,engine starts, idles a short time,then cuts out again.My gut feeling is that the problem lies in the ignition switch or the starter motor.Any ideas??.I thank you all in advance and no wonder I drink with all these niggly electrical issues.PS Battery is new and fully charged.

Cheers Tom

    

2Back to top Go down   Electrical Problems Empty Re: Electrical Problems Wed May 30, 2012 4:13 am

charlie99

charlie99
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goodness tom thats a weird one

kinda sounds like a altenator regulator issue ...an ignition switch .......or a under tank connection from the hall sensors ...kinda thing

the reason i say altenator is that it is suposed start charging over about 1500 revs ...below that on just a start and idle its kinda in a discharge mode till the field gets energised ...i have seen some weird things happen from them when they go funny like ...(usually brushes in the regulator to slip rings ).

the thing that makes it weird is the dimming of the instrumentation lamps but the headlamps stay on and bright

possibly a fuse that has become corroded .....pull them all one by one and inspect the little flange sections of the fuse holder side for corrosion ....and also the blade of the fuses for pitting or sighns of white powdery appearance

if found replace the fuse ....and clean up the contacts of the fuse holder side maybe ...should i say it ....? deoxit is your friend

lets hope someone will come along soon, with the same issue resolved

good luck ol mate


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OElectrical Problems Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

3Back to top Go down   Electrical Problems Empty Re: Electrical Problems Wed May 30, 2012 4:22 am

Tom GR

Tom GR
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Thanks Charlie,should also mention that when engine is warm,the problem seems to go away.(I'm replying to your post whilst having a beer - it helps).Cheers Tom

    

4Back to top Go down   Electrical Problems Empty Re: Electrical Problems Wed May 30, 2012 4:26 am

charlie99

charlie99
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beer o' clock here too tom ...

i guess i better excersize the brain cells a bit later ...giggle


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OElectrical Problems Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

5Back to top Go down   Electrical Problems Empty Re: Electrical Problems Wed May 30, 2012 10:56 am

ReneZ

ReneZ
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Tom, how does the engine stop? Is it a sudden halt or is it slowly slowing down before it stops? First would be electrical, the second would be more like fuel starvation. Any 'clicks' being heard at all?


__________________________________________________
Greetings from Florida! Having a 'new' K  :cyclops:    Surprised-o: 

Rene


BMW K100 - 1985 (0030029) Electrical Problems Rain
BMW K1200GT - 2003 (ZK01223)
    

6Back to top Go down   Electrical Problems Empty Re: Electrical Problems Wed May 30, 2012 7:23 pm

Tom GR

Tom GR
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G'day Rene,thank you for that reply.The engine stops suddenly and there are no clicks. The engine seems to cut out when cold - just after starting.After restarting the engine say two or 4 times,it keeps running (once warmed up).I'll check the fuses and other connections this morning and report back.Cheers Tom

    

7Back to top Go down   Electrical Problems Empty Re: Electrical Problems Thu May 31, 2012 10:33 pm

Tom GR

Tom GR
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G'day All,Started the bike yesterday morning,let it idle for a while and it did not cut out. This morning replaced all the fuses and deOxited the fuse holders. Also,I ran a cable from the battery negative terminal to the frame under the tank where all those earth connections are.I bolted a brass connector plate to the frame,connected the new earth wire to it as well all the other brown wires (earth).The theory is that it give a better groung connection all around.Bike startrd well, and engine did not cut out. So I really don't know what the problem was or maybe still is.I'll keep you posted. Cheers Tom

    

8Back to top Go down   Electrical Problems Empty Re: Electrical Problems Thu May 31, 2012 10:51 pm

charlie99

charlie99
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good idea tom ....hope she holds together ....i suspect cold weather and brushes being too short-intermitent on the altenator slip rings ..
or bad earths on the under tank connection
but every body knows in crazy ...


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OElectrical Problems Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

9Back to top Go down   Electrical Problems Empty Electrical Problems Thu Jun 14, 2012 3:35 am

Tom GR

Tom GR
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Life time member
G'day All,Well,have not had any success with the engine cutting out problem.It still cuts out after idling a little while ( ignition lights go dim headlight remains bright). But after turning ignition off and then on again,ignition lights are normal,when hitting the starter button there is a very loud click (maybe from the starter motor).After a little while,engine starts fine but I noticed a bit of white smoke from the exhaust.When engine is revved up,and and quickly back to idle, there is a puff of black smoke.Decided to look at plugs and found them to be black as-----.Me thinks it is a combination of starter motor and/or temperature sending unit or as Charlie suggests the alternator. Any ideas would be muchly welcome. Cheers Tom

    

10Back to top Go down   Electrical Problems Empty Re: Electrical Problems Sat Jun 16, 2012 2:08 am

K-BIKE

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OK to establish a base line that the system is wired normally and the load shed relay is operating normally, when you push the starter button the headlight should turn off when the starter motor is spinning the engine over is that what happens?

When you try to start after a stall can you hear the fuel pump running?

When it cuts out and as you say the headlight is bright does the headlight turn out when you operate the starter?

Assuming that is the case when the engine is running wiggle the ignition key to see if that provokes a sudden cut out if it doesn't try the same with the emergency stop switch do either of those cause it to cut in the same way as it does when it fails?

If the above don't show anything with the bike running try wiggling the connector to the fuel pump to be sure it is not that causing the fuel pump to stop.
Regards,
K-BIKE

    

11Back to top Go down   Electrical Problems Empty Electrical Problems Mon Jun 18, 2012 3:48 am

Tom GR

Tom GR
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G'day K-Bike,Thank you for that reply.Yes,the headlight goes out when starter is pressed.When engine runs,it keeps running after wiggling ign.key,kill switch and fuel pum connection.I've deoxited the ign. sw.connector,fuel pump connector and the many pinned fuel inj.control unit.Started well and ran well about a dozen times then cut out - same symptoms.After the eng.stalled,a jumper lead from another battery was connected to the bike battery with no brightening of ign.lights.My next step is to check starter motor brushes etc. and alternator brushes.Will keep you posted.Cheers Tom

    

12Back to top Go down   Electrical Problems Empty Re: Electrical Problems Mon Jun 18, 2012 3:56 am

K-BIKE

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Hi Tom,
I am very sceptical it is the starter brushes because the most obvious result of them playing up is the headlight goes on and off as the load shed relay pulls in and out. When it drops out either because there are volts on the starter line or the brushes lose their earth via the commutator either way ignition and fuel pump are unaffected otherwise we could never start our bikes. The reason I asked about the lights going out during starting was to check the wiring to the load shed relay was working as per normal.

When it stalls does the fuel pump run during the start attempt?

Are you getting pulsing on the injectors?
Regards,
K-BIKE

    

13Back to top Go down   Electrical Problems Empty Re: Electrical Problems Mon Jun 18, 2012 5:48 pm

Inge K.

Inge K.
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I would suggest that you check the kill switch (and its related wires in the RHS switch assy connector) one more time.

Since your dash lights dim,..... and the positive feed to the FI relay coil is in the same circuit......after the kill switch.


__________________________________________________
Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

14Back to top Go down   Electrical Problems Empty Electrical Problems Thu Jun 21, 2012 4:02 am

Tom GR

Tom GR
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G'day Inge & K-Bike,Thank you heaps for those replys.H/light goes out when starter button pressed and fuel pump is running.Injectors are pulsing.It started well about a dozen times today and did not cut out. Inge,I have not looked at R/h side switch assembly because we are getting ready for a trip into central Australia (away about 4 to 5 weeks) .Will worry about the K75 on return.Cheers Tom

    

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