So my 85 k100rt decided it was time to cause some trouble,

I was riding down the road and the whole bike, electrical, engine everything just dies no gauges nothing, pull over to the side of the road (after almost getting run over when bike suddenly slows down) turned key to off and back on everything came back up turned to start position (using starter button) and bike started and ran again. So turned around and headed home as I headed home it started doing it more and more with the bike moving I can take key to start position and the forward motion of the bike will restart engine and electrical will come back online but cuts out again a little while down the road.

Got home put the bike in garage and started it and now when I twist throttle in neutral with clutch in the bike dies (electrical and all) like I hit the kill switch, cycle the key and everything runs fine til I twist throttle again.

Not sure where to start on this one any ideas would be great.

Thanks,
Dave

Does sound a bit like the plug to the FI unit is loose except for turning the throttle bit, but definitely worth double checking it is "clicked" into place.

After checking your main electrical connectors (including ground) you should try few simple procedures:
Start the bike with another battery (or boost it with a car battery) and try to twist the throttle when the second battery is still attached to the bike.
You may have a battery with a bad cell. I had a similar problem where the bike would start but would not stay on idle. The alternator doesn't deliver power under 1,500rpm.
I would check the ignition switch too. It may be a bad internal contact (See this page)
If you don't want to open the switch at this time, you can simply jump the 2 connections #15 (green wire) and #30 (red wire) or directly feed #15 from the positive of the battery.

Thank you for the replies I will try all that this evening and see if it changes anything.

Since I'm asking questions I have one about the ignition switch ( I didnt get any manuals or anything with the bike which I resurrected out of a friends backyard) in order to start the bike I have to turn the ignition switch all the way to the right (to the second postion) and once its started I have to turn it one position back to the left to get the brake lights etc to work when I'm riding. Is that normal or do I have something else messed up.

Thanks again,

Dave

Everything should be working in the second position.
The first position is only for the parking light (you can remove the key in the first position but not in the second one)
Maybe somebody had already open the switch and didn't put it back correctly.

Crazy Frog wrote:Everything should be working in the second position.
The first position is only for the parking light (you can remove the key in the first position but not in the second one)
Maybe somebody had already open the switch and didn't put it back correctly.

I can remove the key in any position and the bike will still run (once started) no matter the key position I have to use the kill switch to actually turn the bike off so I must have a problem in the switch too.

Kallack,
Manual for your bike is on Bert's (CrazyFrog) download page.
Go here for some sound advice on ignition cleaning.

http://www.easternbeaver.com/main/stuff/bmw_tech/ignition_switch/ignition_switch.html

BTW, have you ensured you have a good earth?
Finally, hold your main plug in with a tie as I have after a similar experience.

Cheers Ajays

OOPS sorry Bert, I hadn't checked that this was covered by you.

I was just starting to type my answer and see that Ajays replied too.
I would start by opening the switch and check if nobody had previously messed around with it.
This maybe your only problem.

Good luck

Bert

I had the same problem, i cleaned the terminals on the ignition switch and everythings been ok since.
When it dies just quickly turn the key to off then back on and it should carry on.
Instructions to strip the ignition down and clean are in the download section i believe.

Phil Mars just sent me a copy of the riders handbook and this is what they say about the ignition switch:



This K100 rider's handbook is now posted in the download section.

Thanks Phil for this valuable contribution.

Yup thats not the way my ignition switch was working at all. So I pulled it out and found that someone had cut some leads and spliced some others together so I am ordering a new switch tomorrow we'll see if that fixes the problem thank you everyone for your help and if this doesnt fix it I will be back asking questions again, lol.

Oh and Im going to download the rider handbook as well thank you MR. Mars

My pleasure but as with most things on the internet I managed to download it from some other nameless kind soul who thought to make it available.

I had the same symptoms on my 87 K75. I also was going through what I thought were batteries (both cheap and BMW's - it didn't seem to matter). I finally found the ground wire FROM the battery was broken. Keep in mind it 'was' a single strand and the wire insulation appeared to hold it together and it might of even fused/welded back together from time to time due to the current load. I always jumped the bike using the battery positive terminal and frame bolt, thus bypassing my broken ground cable. That problem hounded me for years. I would have never thought to check a cable.

My 85 K100RS would die and regain life while riding sometimes as soon as 1 second, sometimes after 5 seconds. and sometimes after coasting to a stop.

This was fixed when I unhooked the big computer F1 connection and "q-tipped" each blade with NAPA Contact Enhancer CE-1 which is Stabilant 22, $70 for an eye dropper full. I also dabbed a drip on each "blade receiver" but didn't spread them open. Since then I've dabbed all eight blades on my 4 fuel injectors(great), and many other millivolt and some 12 volt connectors, relays etc. You can hear it sizzle off the corrosion sometimes.

Hi Folks,
A much lower cost and by some considered technically superior product Caig Labs DeoxIT is a very good alternative which can be used to treat every connector on the bike.
Regards,
K-BIKE

PS this below is from the CAIG LABS Site: -
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