85 K100 Ignition Blues - K-Bikes.com - Excellence in Motion
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post #1 of 8 (permalink) Old Aug 23rd, 2006, 7:39 pm Thread Starter
Join Date: Aug 2006
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Unhappy 85 K100 Ignition Blues

It all started out when I stopped for a construction delay on my way to Durango Co. a couple weeks ago. I shut K bike down to sit in line and it would not start up again. After trying several times to turn the bike on and off by the ignition switch it finnally fired up and ran like normal. I then stopped to fill up wtih fuel and the same thing happened but this time did not start. I took a friends advice and took apart the ground wires on the main part of the frame, cleaned them up with sandpaper (there was no corrosion) wiped them down with CRC electrical solvent as well as the bolt and nut on the frame, resambled them in the ordrer they came off with no luck. I also replaced the ignition switch, no luck.The start relay I ordered from Bobs BMW was the wrong relay and by matching numbers up it could be the horn relay. I did clean all the connectors on the start relay and did not see any corrosion or notice any discoloration from heat. Still no luck in starting.
Having the gas tank off the bike I was able to get into the compartment with the relays. No fried wires however when I turned the ignition key on the horn relay did some clicking made a humming noise as the tach danced around.

The new ignition switch neeted me the idiot lights go on until I hit the start button then they died. Even though the idiot lights were on the headlight did not come on.

This has been a very frustrating experience because the bike is stored 70 miles away and I can only work on it on saturday mornings when the shop is open and I have off from work.

Is there any possibility a kickstand switch or the start switch could be the gremlin in this bike?

Thanks for any suggestions.

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post #2 of 8 (permalink) Old Aug 23rd, 2006, 9:23 pm
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Location: , SoCal., USA
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These bikes are notorious for corroding contacts and ignition switches going bad. If the bike cranks over, look near the coil pack. The black grounding wire off the coil pack is grounded directly to the frame under a screw head in that area and is prone to loosen or corrode. Also the two-position kill switch has problems.
For more early "K" information that I can possibly give you, please look thru the following site: www.ibmwr.org/ktech.shtml. You can thank me later.

Bruce C
'04 K1200RS Capri Blue(totaled)
2008 Triumph Sprint ST
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post #3 of 8 (permalink) Old Aug 23rd, 2006, 10:23 pm
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On a similar problem with my K100, I pulled the starter, disassembled, cleaned the brushes, reassembled, replaced the starter solenoid and it fired right up. The info on how to do this is on the ibmwr.org tech site referenced in the preceding post. Good luck!
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post #4 of 8 (permalink) Old Aug 24th, 2006, 4:19 pm
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A common failure is for the large plug for the FI computer to get loose under the tool tray. try reseating that too.

BUTT, If you tach needle is jumping around without it running it is very likely the Hall effect sensors have gone out on the front of the motor. It may make noises resembling electrical arcing which is the plugs firing randomly. Some people rebuild those I think which is good since the new ones are expensive

I'm assuming the bike turns over right?
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post #5 of 8 (permalink) Old Aug 27th, 2006, 9:46 am
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Location: Gansevoort NY, Burlingame, CA, USA
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Had the exact same problem with my 85 KRS, take apart the starter (a key electrical ground point), clean it out (worn carbon brushes) and replace the brushes.

04 GT
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post #6 of 8 (permalink) Old Aug 27th, 2006, 11:19 pm
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Originally Posted by NY1200GT
Had the exact same problem with my 85 KRS, take apart the starter (a key electrical ground point), clean it out (worn carbon brushes) and replace the brushes.
What he said...
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post #7 of 8 (permalink) Old Sep 20th, 2006, 2:27 pm
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If your idiot lights are going out, you must have too much resistance somewhere (a short). Check the wiring to the kill switch for voltage and then make sure the switch works. Then check the wiring downstream until you find the loss in volts or amps.
It's a piece of cake to track these gremlims down with a good multi-meter.
Andros is offline  
post #8 of 8 (permalink) Old Nov 26th, 2006, 6:45 am
Join Date: Oct 2005
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Had the same problem...............nearly drove me nuts

After replacing everything but the haddlebars, I by chance, found a broken (cracked) ignition wire.

1985 K100 runs prefectly now
K100David is offline  

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