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51Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Thu Jul 16, 2020 2:55 am

GeoffP63


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@-mek- wrote:Did you check the Hall Effect Sensor? Starter won't crank if the Hall Effect Sensor is not working. Start with checking/replacing the sensor wires.


Hi mek,

I don't think the HES would stop the starter motor from turning over in the K100.

Happy to be corrected on this.

Getting the motor to run with bad HES is another issue of course.

I did however check and test the HES and they are fine.

    

52Back to top Go down   Starter issues – K100RS - Page 2 Empty No go on Thu Jul 16, 2020 3:08 am

daveyson

daveyson
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Close to a wrap up. An earth jumper wire to 85 of the starter relay results in cranking but say at half speed. Without the jumper, it clicks but that's about it, with a tiny movement seen at the alternator. With a jumper from 30 to 87, it cranks at normal speed. The readings are in line with Bert's ICU tests (except earth to 85?)

Bringing us back to an earth fail at 85, pointing to the ICU, or to its earth, again. The same problem exists with three different ICU's, and three different starter relays.

None of these ICU's have been tried in my bike, to see if they're all getting cooked, due to the travel restrictions.

Other than that, testing Amps to 85 and 86, running out of ideas. Maybe both failing, points to the start button, or upstream. The starter relay on my bike was using 0.65 Amps.

Just maybe, it might fire up anyway, even at say half cranking speed.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

53Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 1:38 am

robmack

robmack
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Cranking the engine with the starter motor is not affected by the HES so the HES not a factor in this problem.  Failure of the HES will however prevent sparking and will prevent the ECU from detecting when the engine reaches 700+ RPM to cut out the starter circuit. If bridging pin 85 on the starter to ground improves the cranking speed, then there is a grounding problem somewhere between along the brown/red wire between pin 85 and pin 11 on the ICU and the brown ground wire between ICU pin 1 to ground.

The starter relay coil should draw 650mA or 0.65A approximately if it is working properly.

If bridging the contacts 30 and 87 causes the starter motor to crank normally, then you've verified the primary circuitry for the motor (i.e. supply from the battery positive to the motor and return to ground.  If cranking is weak, then there is a connection problem in the large gauge wiring to the starter relay, a problem with the starter relay contacts, poor contact at the mounting screws for the starter motor or a battery ground problem.

I'll have to re-read this thread to see if I understand the current state of affairs and get back to you.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
http://k75retro.blogspot.ca/
    

54Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 9:52 am

GeoffP63

GeoffP63
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Thanks Rob,

Bridging 30 & 87 it cranks at normal speed.

I'm not sure how to measure the mA draw at stater relay coil.


__________________________________________________
1985 K100RS
50,000 Ks
    

55Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 4:35 pm

Dai

Dai
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Eliminate the starter relay at this point. Pull the two-pin connector off, then earth pin 85 and put pin 86 to positive on the battery. Weak crank = buggered relay. Strong crank = starter relay not at fault.

If the relay's good, go to the righthand switch plug under the fuel tank. Jump the black/yellow and black/green wires. That's the starter button. If that works, you've eliminated the starter button. If it doesn't work, could be that or a corroded killswitch. Jump the green and green/yellow wires and hit the start button. If it works now, there's probably shit in the killswitch.

While you're up there, check the ICU plug (under the top frame rail) is actually secure. It can look connected and not be.



Last edited by Dai on Fri Jul 17, 2020 4:48 pm; edited 1 time in total


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

56Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 4:39 pm

robmack

robmack
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I'd agree Dai. If the relay is trying to engage, and the motor spins slowly, the relay would be the point of failure IMO.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
http://k75retro.blogspot.ca/
    

57Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 4:49 pm

Dai

Dai
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Edited to add more, Rob. It's called the 'brute force approach' Very Happy


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

58Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 10:31 pm

GeoffP63

GeoffP63
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Thanks Dai and Rob for your valuable input.
 
GREAT NEWS – I jumped the green and green/yellow wires to the left switch and hit the start button.
It turned over without welding the starter relay and stopped when the button was released.
 
You have no idea how excited and emotional I was.
 
After 6 months, to feel and hear it react as it should was overwhelming.


So issue is withe Kill switch or connection to it?
 
Just for the record:
 
Earthed pin 85 and put pin 86 to positive on the battery and it cranked as it should.
Starter relay not at fault
 
Righthand switch plug under the fuel tank - Jumped the black/yellow and black/green wires. (tried from each side whilst plug is connected and Ignition on)

Starter does not react as it should. The same click as if it is trying to engage but cannot.


__________________________________________________
1985 K100RS
50,000 Ks
    

59Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Fri Jul 17, 2020 10:45 pm

robmack

robmack
Life time member
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That's good news. Yes, it could be a defective kill switch. Your problem could be that any current drawn by the starter relay would cause a voltage drop across the switch if the switch was bad. That would have lowered the voltage across the starter relay and caused the relay to drop out.

Disassemble the right hand switch cluster and see if you can clean and fix it.


__________________________________________________
Robert
1987 K75 @k75retro.blogspot.ca
http://k75retro.blogspot.ca/
    

60Back to top Go down   Starter issues – K100RS - Page 2 Empty Problem solved - User error on Sat Jul 18, 2020 1:44 am

GeoffP63

GeoffP63
active member
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Hi Dai, Rob and Daveyson,

Thanks to Dai's suggestion to jump the Green and Green/Yellow on the right hand switch plug.

This lead me to check the joins I had made when shortening the harness wires at the plug where it joins the loom.

I then noticed I had joined the green/blue from lights to green on the kill switch, consequently green/blue from kill went to lights.

These two wires are very similar in colour and I was obviously not looking carefully enough when I joined them.

A bit embarrassing but you you what they say, "Shit happens"

If you were all here with me I'd give you a big hug.

Thank you so much for helping me solve this problem.

A special mention to Daveyson who has been very supportive and I think he is as happy as I am.


Regards,

Geoff


__________________________________________________
1985 K100RS
50,000 Ks
    

61Back to top Go down   Starter issues – K100RS - Page 2 Empty No go on Sat Jul 18, 2020 2:18 am

daveyson

daveyson
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Good work, this was way better than a sudoku.

You do realise, don't you, that you're not finished yet? There is still one thing left to do.

Hint, three words, first word; chicken, third word; dance. Photos or it never happened, or YouTube it.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

62Back to top Go down   Starter issues – K100RS - Page 2 Empty Re: Starter issues – K100RS on Sat Jul 18, 2020 5:51 am

Dai

Dai
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Easy mistake to make and very hard to spot. I've had three Ks and on each one of them the blue tracer on that wire has faded quite badly. Because of arthritis I can't handle the BMW paddles, so I change the BMW switches for Japanese ones. Consequently, I've had a bit of experience with that particular wire...


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

63Back to top Go down   Starter issues – K100RS - Page 2 Empty no go on Mon Jul 20, 2020 12:29 am

daveyson

daveyson
Life time member
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Sorry, couldn't help myself.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

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