Finally got the bike started after new plugs and a clean up of the coil connections. When I turned out all the lights I could see blue spark in each plug hole from the outer covering to the block. #2 was the worst, with #3 next, then #4 and #1 had fewer, but some. 

I can well guess that this is a bad sign, probably lots to do with my bike not wanting to start from cold, and the typical suggestion is "go buy new wires"  

But I wonder if there isn't something to be done about them? could one pry off the metal cover (Why a metal cover on an electrical bit anyway?) and go about sealing back up the cap?

also, when under the coils cover I find a random brown wire taped off and not earthed. I thought I had gathered that brown is earth, so should I ground it off? There is a woven steel grounding cable to both housings, but this comes from the ?ignition controller? I assume? everything else that plugs into the coils is from the same loom.

Ah, just got the picture up of the "earth"

Recently had the same thing happen.
little blue sparks to the engine from one coil.

Only long term solution is to replace them I believe.
There is an upgraded version with orange towers (the tower is the bit the rubber lead end plugs on to)
Probably find them fairly cheaply online.

The woven cable I would assume is a means to bypass a bad earth from the brown wires?
They are often found on ex-police type bikes to help reduce radio noise, but I have not seen them on the coils before.

well this was a K100LT with an FM radio and tape deck so maybe it was for that as well. But its the little brown wire I wondered about... think that should be grounded or is taped off away from everything normal?  


wonder if I could just get new spark plug caps and put them on the ends of these leads? All the resistances on the wires were 5-5400 Ohms.

You can play around with them till doomsday and you will never get a satisfactory solution but the leads are past the use by date.  Solution is to replace them with new ones. If you buy used you will just be buying trouble.
I have used these from EME and was pleased with them  About half way down the page
http://www.euromotoelectrics.com/BMW-K-Parts-s/60.htm?searching=Y&sort=13&cat=60&show=20&page=4
As for coils check them and IF they are OK then let them be but I strongly suspect there will be trouble as those old type are renound for dropping their bundle and to be honest it's a wonder they are still there.
As Rossco said get the orange tower coils but be careful as the K1100 also have orange towers and are NOT the same. You can also get coils from EME or there are some dyna brand that do the job but a new carrier would be also needed to attach them.

before you do anything ...

remove the leads away  from the spark plugs with a set of pliers ...and check to see that you have the bobins on top of the spark plugs

many of us have found that the spark plugs have been changed ...and now have the 3mm threaded section ...only ...as the connect to the spark plug wires ....instead of the adaptor to make it 5.5 mm or so inside the lead and cover shroud .

this could well explain why you have seen sparking going on ...

 the high resistance inside the plug tops on the way to the plugs could also translate to sparkover occurring at the coil towers ....if such a situation exists .

quite a few of us have inspected the connection way down in the plug tops after finding this and seen massive corrosion and spark erosion of the metal

you can recover this situation though

carefully with some fine grit paper on a long probe appropriately sized ...after wards treat the contact points with "deoxit "

our favourite replacement plugs is ngk "d7ea "   BUT  you will have to source some "bobins" to fit on top ...either from old plugs or where ever you can

wreckers yards are good for this ...or a handy mechanic

good luck

but as I said check first before anything


in addition
there is an earth terminal attached to a lug under each coil  on most models ...this lug attaches a connection of the inner core of the laminated "core section ) of the coil .
for some failing coils  this can be removed to extend the life somewhat (as there is no real earth connection to the frame of the bike other than the isolation rubbers to the pin through the bracketing setup that retains the coils ).
the reason for the earth in this area might be to help reduce high energy spark emissions when the radio gear is fitted ....as mentioned before

if you do have "lossy coils " (usually on the secondary ) there is no recovery so far that we know yet

final note ...this occurrence of the 3mm threaded section only is a pretty recent thing ...as they used to be supplied with the adaptors- bobins-thimbles  as standard

Thanks Charlie et al,

I did buy the NGK plugs , but had the exact problem you mention. So I returned them for champion that did come with nubs. So that's not it

The coil towers were all in decent shape with minor blue copper corrosion on one. Cleaned that up and also did a rough clean of the inside of the plug caps themselves. 

The sparks I'm getting are from the metal housings to the aluminum block, down inside the plug wells. I do understand that new ones will help, but I'd like to try to insulate these and see if my problems resolve before putting more money in right now

How hot do you think the plug caps get?  Not 500F?

blue - green look down the high voltage tower ?

best to check the coil secondary ...I got some just like that ....they measured open circuit

they should read about 10,000 ohms round about tower to tower on the same coil
which doesn't mean that they don't work ....but could be a good reason for over voltage getting out to the plugs ...at least for the moment

just a question .
I hope you bought the non resistor version of the plug ?  on the ngk that would be dr7ea for the resistor type instead of the d7ea which we all use with resistive leads .
the added resistances could be adding to the issue

sorry don't know the actual temperatures on the plug ...150 c perhaps   ?  300 f ???  others may know ?

I seem to recall you saying this K came from a salty seaside enviroment,(I may be getting crossed up with another member) maybe the salt air has got under the metal caps. When I worked for Honda Australia we used to remove the metal shrouds from the plug caps because we got the problem you are having. Mainly when we had foggy or rainy days. I don't think you couls successfully leave them of a K100 but you may be able to get the metal off and clean under the things and replace them but be careful around the bit where the wire goes in at the top as that is a weak point.

hmmm.  well the NGK that I got were the equivalent listing in the NAPA computer for our bikes and when returning them I got the next equivalent in Champion, 810 RA8HC copper core, nickel spark plugs. I can't seem to find anywhere if they are resistor or non-resistor type?!  

I did pull one tonight and ground it to the engine while cranking and got a bright blue spark...

SO I wrapped the plug caps in a silicone tape, just to see if I could stop the arcing. Now the bike just isn't cooperating and won't start up for me to tell if it helped!! 


I measured the resistance on the coils tower to tower, 2-3 gave me 9,800 and 1-4 gave me 9,4800.  Sounds about right...  how does one check the primary?



All the signs seem to add up, and I know once I get past starting the bike runs pretty nicely, has good power and behaves itself for the most part. I just don't get why the starting issue. 

could an intake leak cause a poor starting that doesn't like the cold start lever??  When I try to start it it will turn over and just not catch in "run" but if I give the cold start a push all the way on it coughs once and then really bogs down... but then gives a good try at starting after the extra cold start before returning to just not catching...  I have gas because the plugs are wet and smell like gas, and I think spark based on the grounded plug, I just don't know what's next... 

and Rick, I think you've got me confused. This bike did come from Florida, but many many years ago, and I've only just learned that myself so I probably never disclosed it on the forum ;-)

Thanks for all the help!!

hmmm that "r" in the model number sounds like resistor included .....not that would neccesarily stop the bike from starting succesfully

ill have a look when i can find the correct reference site for the full specifications ...rather than prices from distributors

im thinking you have a couple of issues ...not plugs alone

The champion you should be using is an A8.

I see you live in Boulder do they salt the roads but even if they dont there is a problem under that metal shield that needs attention or just renew. We used to take the shield off the Hondas but I dont think the caps will stay on unless the shield is in place on the Ks

Aha, bunch of stinkers! I'll have to tell them to renew their parts ref for the bikes! 


Yes, I guess I should just start a full thread about the starting issue?  I have now replaced the air filter, oil filter, fuel filter, new oil, new final drive oil, new plugs, new battery (westco 12V20P from euromotoelectrics) 

None of this has changed the problem I've had since I met her (except to make it worse!) Will not start on cold start, was told it never works well. The battery was poor when I got it, and the only reason it started the day I bought it was using a charger equipped to supply starting amps. Once started everything seems great, and it starts back up no problem while warm.

in addition to what I've replaced there are a few aftermarkets, namely the Supertrapp exhaust it came with. Could that exhaust being blown out maybe affect the flow? does it need more backpressure? 

next time I get it going I'll also spray something flammable at the intake to see if it has a leak...

Thanks tons!! 

yep start a new thread for that .....after you get the "right" plugs in there

you might notice a difference straight away

The K100 I had was a real bugger to start. if you even touched the throttle it would refuse to start at all.
I had to push the start button with my hand away from the throttle and it would idle almost immediately then let it warm a bit (20 seconds or so) and all was good but if you had the slighest bit of throttle it was a no go at all.
Do you know that the choke is really only a fast idle and does not enrich the mixture for starting when cold, the computer does that according to the temperature of the engine and also when you touch the start button the computer gets a signal to enrich while starting even if you only turned it off 2 minutes ago and it is still at operating temperature.

Aha! while I knew that it wasn't actually a "choke" per se, I had actually thought that it did change the mixture. That makes some sense then...

So do you think maybe the temp sensor has anything to do with it? Or is it just the starter button that enriches? 

My '88 K100LT was a perfectly behaved beast, started really well and liked the cold start lever always to start from cold, but then was happy when warm. She started up in seconds after sitting for two years! not so much this one... 

could have a lot to do with it

measure at the under seat connector .....pins 13 and 10

tell us what you get in resistance ...and what the temperature is (should be over 2,000 ohms cold)

I assume you mean the ECU connector? the big daddy? ;-)

ok, so I measured resistance between 10 and 13 (counting from left to right?)  and got nothing. no resistance, no buzz, at 200, 2000 and 20000 settings...


So where is that temperature sensor located? I think I need to check it or at least its connections!

there are 2 brains
one the ecu ....electronic ignition control (electronic control unit ) ...under the tank
and the efi  .....electronic (fuel) injector unit ....under the seat
the temp sensor feeds the under seat brain .


way deep in behind the radiator
sorry its a "fairing off" job ...lower right hand side to get across to the sensor on the engine water outlet tube (return line to the radiator )   which is actually near the left hand side ...on the head .
but the connections face to the right hand side .
its good to undo the air cleaner box and get it out of the way also .. just so you have room for some movement

the clip that retains the connector is like those weird injector plug connections so a small screw driver or fine point pliers might be needed to assist in getting it apart .

hope that helps

there have been several posts in the forum about doing the job

try using the search feature ?

can I say ....whilst your in there.
clean up the fan connections just in about the same place  they are often a source of frustration when the hot weather returns and the fan fails to operate ... just a heads up

Thank you so much for all the help,  


Lucky me, the fairing is already off! I'll search out that sensor and see how its doing. I just had the airbox apart to replace the filter, so now I know how to manage that too. 


Funny thing, while checking the EFI (as I now know it  ) I accidentally tried starting her with it still disconnected!! it sounded about the same as when I try to start it cold normally so I walked away, but then when I realized what I had done I reconnected it and tried it just for fun.  Bam! she started right up and with the cold start full on too!!  

I'll have to see if this behavior repeats itself or if it was just that it got a good tickle in the chambers from the first attempt! 


Also, now that it started I was able to look for the sparks again. Having gone ahead and wrapped the plug caps all with a stretchy silicone rubber plumbers tape (no glue, just a strip of silicone good to 500°F) I saw no sparks!! (I know, it looks like crap, but its a proof of concept before buying new wires)

 

So this is with the Champion resistor plugs! So it runs, and runs well, with no stray sparks once the outside of the caps is insulated with both resistor caps and plugs!  Is there any chance this will blow up the coils with the added resistance?

Those multi pin plugs on the computer are renound for needing to be unplugged and then cleaned or just as you did plug it back in.

I doubt very much that you will damage the coils but you will erode the plug gap much quicker because of increased current.   Also the spark will not be at its best

ok, that makes sense. I talked to the guys at NAPA about how the "recommended" plug in their system wasn't ok based on your input. They agreed to let me return the champions as a "defective" part and keep the nuts!  Then I can buy our preferred NGK D7EA's and have nuts to use them! win win.

Yer done well.

I would add that with the extra resistances in the plugs ...the (current) spark intensity is reduced quite significantly ....meanwhile the coils are doing hiccups trying to dump the energy quickly ...but through a higher resistive load to earth (equals LESS current ) it takes longer to dissipate ...which also buggers up the dwell for the next firing event

some other k riders have reported that the ignition and acceleration always seemed "fuffy " to them
well that's the way it was explained to me

changing the plugs from inbuilt resistor types ...produced real effective solution and a new appreciation of our old k bikes ....

 well that's with "standard " factory resistive leads

I guess they always thought that the resistor type plugs were better in some way

all food for thought

great to see you have a solution to the spark jumping ...a revelation of back to basics in a sensible way ...cheers !

well for now it seems that unplugging the EFI was the trick. there's still a small battle to start, but its way better than it was. New NGK plugs with the caps from the others are running well. 

I will need to replace the resistor caps eventually. I found NGK LB05EP caps for not too much each, but I wonder if that rubber seal on the spark plug end is going to fit down in our blocks? 

I also wonder how important is it to keep the resistor caps? would it cause too much amperage? I don't have a radio, and I don't really care if I make someone's car radio fuzzy for a second. Would it run better? or should I just get resistor caps like it has already?  

you don't need resistor caps either

if you measured the leads at about 5000 ohms  that's all you need  you don't need to add another 5000 ohms to the circuit

the leads that bmw uses are already resistance wires (if they are the silicon type )with straight fit rightangled  and non resistored caps ,,,

You need the resistor caps to match the impedence of the coil and plugs and wires. If this is not the same or within about 10% then strange things happen, one being overheating coils and poor spark.
With todays high power ignition systems you need to have things just right or the power gets disipated in the wrong place and because of the high power the frying is very quick in many instances.

Oh man! these new fangled vehicles!!! Where's my old BSA when I need it?!?!  (oh yeah, right there beside the BMW> its what gets used when this stinkin' beemer won't start!  )

ok, so my idea was to use the BMW wires that are on there, and only replace the caps. Since the BMW caps are metal shrouded, it only makes sense that they are going to conduct eventually. 

SO! will new caps screw easily onto the end of existing BMW wires? is they are resistor wires will they be hard to make contact with the metal screw? (had issues using a carbon lead on the BSA once)

and are we sure that the wires are providing the resistance? not the cap?  

I see why the standard answer is "go buy new ones" but I am just stubborn that way...


Thanks tons!! 

of corse you could just go down to the local car parts place and buy the elcheepo (but works ) silicon leads
 about 5 bucks each
you wont get the nice near right angle hood for that price

 , just confirm that they measure somewhere in the 5000 ohms area for each one

luckily,. I haven't seen carbon leads now for many years .
but im not sure that silicon leads take a screw headed plug top well .
but its worth a try

I used the blue silicone leads on my K100 and they worked just fine. I had to get a couple that were longer than needed so as to get the 5000 ohms but BMW also has them double back for presumable the same purpose.

ah, interesting, I always thought that #4 was doubled in order to allow you to move it when it was off the plug, but that makes sense!! 

I guess I'll just make sure that whatever I get gives me 5000ohms when I'm done with it!


Thanks guys! I have been reading your resto thread Charlie, now there's a novel!! 

I use this one, it also has the right angle.


Dick

good find dick

that does look perfect, and just like the ones on the NGK wire set EME sells! 

So do you have a part number for it? I have only found the resistor lists...

try it here.
http://www.ngk.com/product.aspx?zpid=20072

great, thanks! So that looks like it will reach deeply enough, and you already use them so they fit under the cover, right? 

the only thing that I'm wondering now is will they work ok with the existing OEM wires?  having not taken apart mine (without parts to put it right back together) I'm going on the common knowledge that the OEM are resistor wires, not resistor caps...?  Would I want to put new wires on if I go with these?

I would put new everything including the coil ends. If one component is breaking down the insulation the othere probably wont be far behind.

aye ! 
do it once ...then forget it

well sure, but this is a learning process as much as anything 

nods head .....ifn you can play around and learn ....without it costing too much ....all the better

A few components you'll need:
4x oem number 12121459887






4x oem number 12121363327