Some gremlins are working my bike over.  help...

I'm rather new to this forum and am still a bit unfamiliar with the etiquette of writing and such.  downloading pictures etc - I'll get there one day. 

My handle is Cracked Canoe.
I live in pickering Ontario (close to Toronto) 
my ride is a 1985 K100 RS with 90+ k on the odometer.
boy do I love that machine.  She's no beloved wife but pretty close.....

anyway - Here we go.

The other day I made a few stops in short order.
beer store to pick up some of my favorite beverages (a few bitburgers, a box of keiths india pale ale, and a couple of Lowenbrau), then a drive about 1 km to gas the bike up (with premium - nothing but the best for the girl) and lastly, a stop at the bank around the corner from the gas station before heading home.

Coming out of the bank I put the key in, turn the ignition, flip the kill switch from the right to center.
no instrumentation lights, zero, nothing.
flip the kill switch back and forth left - center - right - center still out of luck, lights faint to very dim. 
press the start button still nothing..
thought it might be the gas tank -  maybe no vacuum or maybe overheat???
think think think...
pulled the key from the ignition to unlock the seat and retrieve the manual that resides in the pocket below cause, when all else fails....
Key back in the ignition, turn to the on position and the dash lights up like a roman candle.
Green light of the neutral, red battery and oil lights and yellow choke light - like Christmas lights came early.  Needless to say the old girl started like she was in a hurry to get going.

After getting home I plugged in for the trickle charge.  According to the bills from the previous owner, the battery was replaced 4 years ago.  Might be the source of concern. A week goes by with no further problems.  I make a mental note to purchase a battery.
 
This morning as I am leaving for work.  Gremlins...  its a no go.  same issue.  no lights period and no start button zilch.

This evening, back out in the garage I narrow it down to the keyed ignition and that it has some fault in it. It doesn't happen all the time, but, by trial and error, I can re-create the faulty / dim lighting on the dash and by manipulating the key and the position of the key in the ignition \I can get the bike to turn over.

So.  Where do I start?  is it a simple fix? Do I need to remove the key assembly? if so what is the best way to remove the key ignition and what should I watch out for? 
Has anyone come across this before?
I figure this is electrical and a loose connection or a frail wire - could I be wrong?
any thoughts, help or direction is most appreciated.


Thanks in advance.

Cracked Canoe.

Hi cc.
Had a similar problem with my 1990 RS after squirting wd40 into keyway.Thought it was a good idea at the time.Think your set up will be a bit different than mine but you will need to get at and clean the contacts in the switch under the key.Use the search tab as there are good articles there.May be fiddley but not that hard.Good luck.

It is most likely the ignition switch itself they are prone to problems as they age (just like you and me).
Most likely it's just dirty and needs a clean. If you hunt around or search the forum I am sure there is a bit about cleaning the switch which is on the bottom of the barrel the key goes in.
I have never had one apart but firstly you remove the centre dash pad and then you can get at the whole thing.
I think there is a small slotted grub screw to get out then the switch comes away from the main body.
I wont give any futher instructions but as most things BMW they do come apart but be VERY carefull not to lose any little bits and probably best to take it apart with it inside a plastic bag as the small thingies have a bad habit if going sproing and heading for the most inaccessible place and staying there in hiding untill just after you give up and get a replacement, if that is you know what that little thing that zinged past your left eye was.

Other things can be battery terminals need cleaning and any of the plug points on the way to the switch.
We usually recommend that new owners go over every electrical connection on the bike with Deoxit (an electrical contact cleaner) and especially in your area where salting the roads is a common thing.

Check the section of the loom where it is cable-tied to the frame. You will need to split the sheath. You may find that the wires have frayed inside.

CC,
  First and importantly, DO NOT use the kill switch at all only for emergencies. Use only the key for start and stop....as per BMW advice.
So this where your problem is and not the ignition switch in my opinion.
There is plenty of info; here but somewhere I have a write up with pictures of dismantling kill switch and ignition switch. If you need it I will plough thro' my stock...! [but I hope not]
                          It is a great Bike and this a great forum thanks to Crazy Frog and his team.
                                             Ajays

Just to pick something up from your post:
"with premium - nothing but the best for the girl"
Whatever the name, a higher octane fuel than the engine was designed for is not better but very slightly worse for that engine.
In Europe we used to have Normal and Super fuel, the names mean nothing it is just that one burns at a different speed to the other.

BikerBoy,
   I second that, never top premium but unleaded is OK.
If you continue to use the so called best, get a lead additive. You will gain nothing...!

I beg to differ Bikerboy and Ajays, this is taken directly from the riders manual for the K100 up to 1988, the next version says the same.
Use only super (premium, 4- star) fuel to
German Industrial Standard DIN 51 600
or equiva lent, with a minimum octane
number of 98 (Research Method) or 88
(Motor Method).
No additives (for example upper cylinder
lubricants) are needed.

Page 64 of my Riders Handbook:
Type of Fuel#
Unleaded regular grade fuel (2-star) to DIN 51607 or equivalent, min octane number 91 (RM) or 82.5 (MM). Alternatively, leaded fuel may be used.

Strange how they seem to be saying two different things.

My ignition switch (key) is so dead the previous owner spliced in a toggle for the on / off. It has been working fine, but recently I have had a couple of intermittant shut offs at speed, then it came back after 2 of 3 seconds. I did maintain fuel pressure (have guage), so I am thinking connectors or ground
art

Rick, Old Mate,
 To  each his own..CC has the earlier engine with the high lift cams and more powerful than the latter versions. Mine at the present time is a 1983/4 and I run on low unleaded. I can get well over the Ton [100 mph].
Mind you, it is the Motor Sport version.
  The main problem CC needs to keep in mind is the thin wall coating in the cylinders and too low revs can damage that.
Can't blindly follow the manual. If you fill up with oil to their figures and not the visual optic centre level you will experience oil leaks....all these errors I experienced during ownership of the K series.

With a smile...Ajays

Me thinks that they don't really know they are talking about
Direct from my K1100 manual
"unleaded middle or premium grade fuel, minimum octane number 89 (Anti Knock Index (r=m)/2) or minimum octane number (RM) and 85 (MM)."

I got cut off by a phone call (she would talk the ears off a wheat bag).
I didnt see your post till just now but what evidence have you got for these highlift cams mate, I keep hearing about them but have never seen any listing.
The only cams I know of that were different were for the US market which were slightly less in duration to std (for the california smog laws) and then in 86 or 87 they reverted to the normal cams used elsewhere.  I think that is where the "highlift" comes from in that the US market did get better cams after 86.
I agree with you about the Nicasil coating it is very prone to failure with detonation and so I have always run our 98 octane RON. My K100 used to detonate quite a bit the few times I got caught out and had to use 91 or push it.
The K1100 always gets 98 and so does my 320i car although the car does have knock sensors and when it knocks the timing back I really noticed it. I put 91 in by mistake once.

Before tearing in to the IGN switch, lift of the tank & clean the connector between the IGN switch harness and the main wiring loom really good with deoxit.
 It was the source of my failure.
Regards, Ibjman

This is an earlier quote from GWK100RS a member here.
More or less my view Rick  

  I have done a lot of research on this subject , and found most of my information's on cams on the vintage mini cooper web sites(these guys use K100 2an4 valve and K11and12 heads on there mini's to get more power out of them). As far as I could determine in 85 the European and 49 state bikes had the hotter cams(284 duration and higher lift) in 86 all U.S. bikes received the smaller cams that the California bikes have, I think because of tightening emission controls in the U.S. The K100 4v suffered the same fate with the Euro bikes getting the hotter cams and the U.S. getting the smaller cams. The K1100 all received the smaller cams do to a 100 hp limit Europe, the K12 RS and GT all have the hot cams and biggest throttle bodies(38mm). I installed the hotter cams and throttle bodies and fuel rail(3.5 bar regulator instead of 2.5 on earlier bikes) from a K12RS on my 96 K11RS along with a Ramus exhaust and a tweak to the motronic 2.2 and the the power difference put a real big permanent grin on my face. The engine revs up so fast in 1st and 2nd gear that the engine beats the tach to the rev limiter.

What is the deoxit equivalent in the US?

No equivalent.

get it here:
http://www.allelectronics.com/make-a-store/item/D5S-6/DEOXIT-R-CONTACT-CLEANER/REJUVENATOR/1.html

DeoxIT is made in the USA by Caig who can be found on the www.
Regards,
K-BIKE

Just a note regarding the deoxit treatment. I applied the spray to the connectors and plugins under the tank. One of the pins on the ignition switch plug looked particularly oxidized. After reassambly and a couple of tanks of gas (with bursts up to 125 mph), all is well. No engine cutting out momentarily at all.
Thanks for the good advice

I'm happy the treatment worked for you! To me, it seems like a critical "weak point" where those two connectors join.
  You'll find many points in the future to use the de-oxit. In fact, I'm now on my second can!
Regards, ibj....

G'day, Had a similar problem on my 75 where the instrument lights went dim but headlight was still bright. On Inge's advice bridged the red and green wires behind the ignition switch when the fault occurred.If the instrument lights came good, the fault is in the ignition switch with a bad contact. The switch is fairly easy to pull apart but watch the springy bits.Have had no problem since.
Cheers
Tom Grabau