BMW K bikes (Bricks)


You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


53cr3t5quirr31

53cr3t5quirr31
active member
active member
Okay so I have a 1987 k100rs I have turned into a cafe racer. The bike has only 30k miles and I am having a load of issues. Went to start the bike today and nothing... I click the starter it does a quick jolt of the starter then cuts out.. immediately I think it's the hall sensor.. nope hall sensor checks out fine... all of my fuses are good.. all connections and electric grease on them.. as I was trying to get it to start the ignition coils started to buzz almost as if they got stuck or something.. I unplug the coils from the harness and bam! The bike constantly turns over but no fuel pump.. strange... I check the pump with a 12v jumper it works I then go to the under tank connection and I am getting 8volts with the starter depressed and it jumps to 10volts for 1.5 seconds after starter is let go... changed out FI relay.. nothing.. cleaned the starter winding and brushes.. nothing... swapped the load shed and light relay and the light still works.. only 8-9volts at number 6 fuse.. their is continuity from the computer to the FI relay but it is always at 0volts  and does not carry 12volts with the ignition on.. do i need a new computer?? Anything I'm missing? Sorry for the long post I wanted to be thorough

    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
Edit*** just to clarify. With the kill switch in the run position and the key in the on position their is no 12v from pin #7 to the FI relay and when i press the starter their is not change in line voltage (should be +12volts when when key on and grounded when starter is engaged) let me know if I'm wrong thanks again!!!

    

Laitch

Laitch
Life time member
Life time member
53cr3t5quirr31 wrote:Edit*** just to clarify. With the kill switch in the run position and the key in the on position their is no 12v from pin #7 . . .
Pin #7 of the ignition control unit, pin #7 of the fuel injection control unit or some other pin #7?


__________________________________________________
1995 K75 90,000 miles
    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
Pin #7 of the ignition control unit

    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
Okay guys update****
I checked the wrong pin :/ I have now checked the correct pin #7 (not #2 as previously) and I am getting 8.8 volts with all the switches in the on position... when I go to crank the bike it drops down to 6 volts...
Also when I plug the coils back into the harness it's still only blips the starter before cutting out...
Dead CDI??? What's your thoughts?

    

Laitch

Laitch
Life time member
Life time member
53cr3t5quirr31 wrote: What's your thoughts?
What is the resting voltage of your battery right now?


__________________________________________________
1995 K75 90,000 miles
    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
12.6 volts

    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
*update
I just checked pin #10 at the ICU and I only have 9.4 volts

    

Overkill

Overkill
New member
New member
Sounds like a bad battery to me.

    

Point-Seven-five

Point-Seven-five
Life time member
Life time member
12.6V sounds like a weak battery/one that won't hold a charge.


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
I'm running it off a large jump pack so I don't bleed down my brand new yuasa. All other fuses have 12 volts except fuse #6 it has around 8-9

    

Rick G

Rick G
admin
admin
Firstly I would recommend replacing all the fuses. They get some internal corrosion and will fail when they look OK.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
Already did that every fuse is brand new less than a week old

    

Rick G

Rick G
admin
admin
The next step is to systematically go back along the wiring path and check voltage at each junction. My first place to suspect is the blue green wire at the ignition switch then the kill switch Green/yellow wire. I will say that a bad connection is responsible for the voltage drop.
The ICU and ECU will only work if the voltage is over a predetermined voltage of (I think) 9.5Volts, but it is in the area of the voltage you are finding.



Last edited by RicK G on Thu Sep 07, 2017 9:55 am; edited 1 time in total (Reason for editing : Duck was getting picky yeah it was green so sue me LOL)


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

53cr3t5quirr31

53cr3t5quirr31
active member
active member
Okay I'll check for breaks in the wire. I believe the CDI is powered on because it triggered the FI relay and that is controlled by the CDI
Will report back

    

duck

duck
Life time member
Life time member
RicK G wrote:blue wire at the ignition switch

What blue wire?

Every ignition switch I've seen only has:
Red
Green
Gray
Gray/Blue


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
98 Taxi Cab K1200RS
14 K1600GT
http://www.ClassicKBikes.com
    

Sponsored content


    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum