rawdonball wrote:To add to what the Kaptain was saying - I know my K100 wouldn't run with temperature sensor plug detached. I assumed this was due to the FICU seeing this as an over temperature situation sufficient to warrant shutdown. My recollection was I could get it to kick over / fire up but that it would not run

im sure you meant "under temperature " situation rawdon ....remember the temp sensor is high for low temp   ...so infinity is close to - 273dec c ?  lol ...where as .. if  it approaches 0 resistance (short circuit )  the ficu would shut down with over temp signal .

ill bet it was pumping heaps of fuel that it couldn't ignite ...ill bet you knew that ...but like me, I forget things as in typing ....trip ..face plant ...shoot ...bugga

You are right of course Chaz...

I think I also tried with plug earthed - also no running (just to add to my confusion!

"if it approaches 0 resistance (short circuit )  the ficu would shut down with over temp signal"
The ECU wont shut down in an over temp situation but will prevent you starting till the temp goes down to a predetermined level which from what I have seen is a bit above a normal running temp.

If the temp light comes on that is 113°C, if you keep running you can cook it but if you stop the engine then it will not start.

indeed rick

All good. However escodsm has simply gerry-rigged his machine to attempt to get a voltage from the contacts of the starter relay which would confirm that the starter motor will turn when its installed.
It seems that the starter relay control coil is not firing to close the contacts. There's voltage at the starter button but I wonder if there's voltage on the starter relay coil connector (yellow/black wire) when the starter button is pressed? Or is the ICU is not switching the starter relay control coil circuit to earth?


Possibly the electrical connectors are corroded... judging by the condition of the machine in the photo escodsm posted earlier. 

As promised
Here are some pictures.  A wiring question is at the end of the pictures.


Here we see I have the three connections in place per you guys' recommendation



I still get NO response from the starter button.  I tested my new starter relay and it's fine.  I touched the two leads on the large stabs and the starter engaged.  But nothing from the start button, clutch in or not.  Then I found these two wires cut on the loom going to the right side controls.  They are both gray, and I cannot find these anywhere on the wiring diagram for this bike.  The other side of this plug if you look at the gray wires, they loop all together.

Here is the bike as it sits now. I spent all day tracing wires, testing resistance, looking for continuity.  The headlight is mounted now(after I took the pics) and it works.  The horn works.  The starter and starter relay are good.  But I cannot get the bike to turn on its own.  Thinking of ripping all the wires out and buying a new harness entirely.  This is ridiculous.

The right hand connector pinout seems to be wrong.  The wire colours don't look like they match the schematic.  Is it possible the PO swapped pins in the connector shell?

For example, Pin 1=Black with Yellow tracer and yours matches.  Pin 2 = Green with Yellow tracer and yours matches.  Pin 3 = Grey or Grey with Blue tracer (can't tell from the photo) but on the schematic, Pin 3 should be Green with Blue tracer.    That means Pin 4 on your connector looks to be double Grey but, in the schematic, Pin 4 should be White with Yellow tracer.  It's hard to tell from your photo. Can you confirm the coloring for us pin by pin?  Which pin contains the clipped Grey wire?

Sure, definitely! I'll grab some better pics right now.  Just a 5 min walk, good excuse to get outside, was bored anyway haha

OK back - Yes I know the bike is filthy, this poor girl sat outside for years under a tarp on a dirt road/driveway before I rescued her.  Today I took the ground off in the top center of the frame and ran some sandpaper through the entire area to clean up the connection to ground.
As for the RH harness I am not sure what pin number is #1 - but let me know whatever I can do to help you help me 
Here is my approach to the right side of the bike:









Here is the harness connected, I peeled back the protective sleeve, and I am displaying the harness side of the wires.  Why are the grays looped like this? Looks weird....









Here is the bike side of the harness connector.  This is where the two gray wires are cut - from the frame(body) side of the harness.  Closeups follow:

About the two grey wires in a loop at switch side of the connector: this is normal on a US model which have lights permanently on (no on/off switch).

About the grey wire loop which have been cut on the harness side of the connector: looks like a PO have powered the kill switch from the headlight circuit and later found out that it wasn't a good idea.
This would be the reason to your start problem, check if you got power on fuse #1.
Second, you would have no headlight...unless LHS switch assy/connector also have been modded.

I would guess that you find more mods in your wiring system.

Inge K. wrote:
Second, you would have no headlight...unless LHS switch assy/connector also have been modded.

I would guess that you find more mods in your wiring system.

Well, interestingly...the headlight does work.  The left side control harness was replaced by me and the horn works.  There's no flasher relay so I cant test those just yet, but the complete harness I just bought comes with the entire relay box heh heh :pirat:


The left side has a ton of empty female connectors.  I will grab a couple pics of those.  And, there is one connector on that side with three leads cut.  One wire is a very light blue - the only "Sky Blue" wire in my manual is for the alternator, and that is there - so no clue what this is.

UPDATE!
Got my new harness from California today at 3p. Got the bike to fire up with the start button at 6:30p!

Turns out, after fixing the chewed wires of the coolant sensor, it was the freaking kill switch causing the no-start! Discovered this by testing it for continuity (nope), then jumping the kill switch at the harness, button turned the starter. Open up the right hand control to see there is a missing part! After popping off the c clip from the underside of the start button, and pulling the kill switch apart, there should be a metal piece to make contact when the kill switch is to the center position only. There is no metal piece in there.


Anyone know the piece I am talking about?
Anyone have a drawing of it?

This is a picture of the back side of the kill switch. Is it this beryllium copper contact which is missing?



If not and it is one of the contacts within the housing itself that is missing, it's time to buy a new RH switch assembly.

Yep, that's it.  I'm at the office currently, else I'd put a comparison photo up.  
But basically that red plastic kill switch piece, on my bike, has no metal *anything* there, beryllium/copper/brass/alchemy whatever it is 
The contacts are present in the housing.

I thought about sticking a washer in there or permanently jumping the kill.  Or, I may just customize it and build it into the seat like a lawn tractor - which makes more sense to me as a kill switch - than a f*&%ing hand switch.

(I slip off the bike, it goes across the roadway into a culvert, last thing I am thinking is to flick the kill switch on the way down)

But say I was interested in obtaining this beryllium washer thing....anyone have a bad RH control they wouldnt mind scavenging?


EDIT: found where you got that k.s. photo - and grabbed this screen shot from the same page


Mine looks just like this - except no springs in those two holes....(now I know springs belong in there!)

If you could find the right sized brass washer and a modicom of ingenuity, I think it would be simple to make one.
A seat switch would be impractical. You would not be able to stand up on the pegs to have a good fart  
or start your bike unless your were sitting on it.

Kaptain Holister wrote:
A seat switch would be impractical. You would not be able to stand up on the pegs to have a good fart  

Hahahaa!! Great point, as I would be very sad if I could not do this

THANK YOU for the closeup pics....ingenuity is my thing - but here's another question:  

Since I am custom-mounting the ignition switch to the right side (just below the tank near the radiator fill neck), how about using one of these right next to it as a kill switch?


Then again, the starter button itself bangs off the contacts at will since there is no spring plate in there....so a less hacky solution would involve fabricating a "Beryllium contact plate", or, just biting the bullet and buying a 'new' RH combo...

I think they're made from 'Unobtainium'  
I can't see any reason you couldn't mount that switch there except it may be hard to get to if the machine is on its side. Handlebars are the best place for it imo.

The two springs and brass contact plate are not a part of the starter button mechanism. The starter button relies on the spring under the button cap to pull it back off the starter contacts which are the 2 tangs below/under the kill sw contacts.

Switch blocks are available from Motoworks or Motobins.... very pricey. I think they have secondhand as well.

Kaptain Holister wrote: The starter button relies on the spring under the button cap to pull it back off the starter contacts which are the 2 tangs below/under the kill sw contacts.

Okay, I understand.  Then the issue is that my starter button cap is broken off and only the inner cylinder remains.  Preparing the bullet for biting. 

Just remember to bite down hard as you pull your wallet out. It won't hurt nearly as much.

There is life after a missing starter button event. You aren't the only one to find it has pinged off into the scrub on the side of the road somewhere between where you were half an hour ago and home.

Reading this thread about the RH switch block turned on a light in my brain about my habits. That is I don't use the kill switch to turn the bike off, only switch it off with the key.

No particular reason for doing it that way - just never thought about it and I think I've always done that on all my bikes. So wise ones! is there any drawback to switching the bike off with the ignition key rather than the kill switch?

Thanks

I always use the kill switch then turn the ignition off when I remember. It's never caused a problem except for an occasional flat battery (twice that I remember).

if I was a gambling man gaz ...and im not

I would recon the ignition switch has better contacts that might last longer than the kill switch ...

my reasoning is that at energisation the inrush current may be better handled by the ignition switch contacts ...my thinking is that if I used the kill switch all the time it would wear and arc the contacts over time .....and I really don't need another reason to work on those expensive switch blocks out the end of the bars ...we have seen that in many cases that the contacts out there are not designed for ease of access and serviceability ...besides being under rated in my way of thinking

just my thoughts mate

Ok bike is mostly back together now. My battery reads 14.8 volts.
I squeeze the clutch and press the starter.

I can hear the fuel pump going. But the starter just does a weak, pathetic half crank. Button still in, fuel pump continues but starter engages every other second, then stops for a second, then engages for a second.
I stopped there after 2 attempts out of fear of welding my relay shut, as I have heard of that issue on this forum.
I clipped my meter to the battery while cranking....goes from 14.8 to 11.5 then back up to 13.6

I think I have a crap battery, gonna try jumping it With a car battery. Car NOT running! And I'll report back.

If the voltage only drops to 11.5 then the battery is good I would get the starter out and fit new brushes and bearings. It sounds to me like the starter armature is draging against the magnets because of badly worn bearings.

Nice, my friend said the same thing earlier. Gonna break it loose and out of there probably Wednesday now, New York time, it did the same with a car battery.
Thanks Rick

escodsm wrote:Button still in, fuel pump continues but starter engages every other second, then stops for a second, then engages for a second.

This is a symptom to a bad hall sensor.

Oh no! Yeah I got the starter apart, and it's dirty, but not terrible. A good cleaning with some emery cloth.
Hall sensor....the one under the pan? Near oil drain?

No. Front of the engine, under the T-shaped cover, left of the oil pump. Easy to get at and £48 from Motorworks s/h.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=10&M=40&Ct=KA&SbCt=BA_10_40_KA_30&spPage=2

Too late now, but don't ever clean the starter motor commutator strips (the copper bits) with emery cloth or wet'n'dry. Two reasons:

1. Both of those materials will embed bits in the copper and cause the brushes to wear prematurely. Not fast, just prematurely.
2. From new, those copper strips contain micro-pits. The carbon from the brushes fills those pits and makes for a better contact surface.

The most you should be doing (unless the commutator is really dirty) is carefully scraping the crap out from between the copper strips.

OK - put the starter back in, cleaned it up with contact cleaner, thats all.

Here's a video I just made of the start situation.  Apologize for the rotation of the video; it's the audio you want anyway...

Best way to clean a dirty commutator is using a eraser.

If you're a bit handy you can change the sensors yourself......
mark up the exact position to the backplate relative to the camcover...

This is a direct replacement...http://www.bbautomacao.com/home_hall_effect_sensor_cyhme56.html

If you search a bit you find plenty of how to's on this forum (links) and elsewhere
on the net..........R models using the same sensors..search these how to's also.

But finding a used complete unit would be a easier solution....

Do you think this could be my sprag clutch? Based on the video above?


Edit: Unplugged the HES completely and tried starting the bike.  Does the same exact thing as the video above.

UPDATE

You Professional BMW guys let me know if my below assumption is correct.

Starter works...
1) If I jump + battery terminal to starter, the starter freely spins like crazy.
2) If I press start button, I can hear fuel pump, and the starter twerks for a second and then stops.
3) I can turn the motor over by removing the plugs, which appear to be in good health, and turning the rear wheel while on center stand.
4) I removed starter again, and looked inside.  I can turn the intermediate gear with a screwdriver, COUNTER CLOCKWISE, but it is very hard to turn CLOCKWISE.  When I can turn it Clockwise, a drinking straw I placed in one of the cylinders pushed out, so I know I am turning the motor by going CLOCKWISE with the intermediate gear.

MY ASSUMPTION is, that because this intermediate gear is functioning, and it is connected to the Sprag clutch, it is operating as it should be, (A one-way clutch).  Is this a good enough test to see that the sprag clutch is working?
I DO NOT want to open her up.  But I will if I have to. 

PS - I checked the rotation of the starter pin, and it goes CLOCKWISE, which means it turns the intermediate gear COUNTER CLOCKWISE, and thus has no effect.  What is going on here???


EDIT: Just found this related issue

Fixed the starter rotation direction to CCW, in order for the intermediate heat to turn CW...

Jumping pos + from battery to starter turns motor and wheel in gear.

Pushing starter button fuel pump primes and starter = "clunk"

Perhaps not getting enough from the battery? Not enough amperage? 

Can't be the sprag clutch though, if I saw the starter turn the wheel and the motor.  So I think we've eliminated that....

Check the voltage across the battery when the engine is being cranked. Fully charge the battery before any attempt to test it. It should be no less than 10.5 volts and even it being that low means the battery is not charged or is on the way out, a new fully charged battery will only drop to 11.5 volts.
Don't crank for too long as this can weld the starter relay contacts together.
If you are in any doubt take the battery to any good auto shop and they will test it.

Hi Rick

From post #72:
My battery reads 14.8 volts.
I squeeze the clutch and press the starter.
I clipped my meter to the battery while cranking....goes from 14.8 to 11.5 then back up to 13.6


However it's only an 18Ah battery....I think I remember this being an issue on my old K that I used to ride....Now that the starter is turning the right direction I may try a car battery cold jump and see what happens.

If the voltage drops to only 11.5 there is nothing wrong with the battery.
Try a lead direct from the + of the battery to the terminal of the starter that will tell if the relay is at fault by bypassing it. Also make sure the ground at the - battery terminal is a good connection and the 6mm allen bolt where it attaches to the gearbox. One other thing in the earth circuit is the 2 bolts that bolt the starter on, make sure the surface where they meet the gearbox is clean.
Earths/grounds are a much overlooked thing in electrickery and can lead you a merry chase given a touch of corosion.
An 18Ah battery is all you need, many of the LT and the Police models came with a 28Ah but it was fitted because there was often a high load when the bike isn't running like those dreaded blue and red lights occasionally seen in the rear view mirror.

Grounds have all been touched up and are solid.
The starter turns fine when jumped to (+pos) battery terminal.
It also turns fine when I jump the large tabs on the starter relay.

Having spent some time researching this, it may be the Ignition Module up near the forks.

escodsm wrote:
Having spent some time researching this, it may be the Ignition Module up near the forks.

This is sounding like more of a possibility.

You could try manually grounding the relay coil (Brown/Red to ground) with a clip lead and test starting the bike to see if it turns over. If it turns over properly, the ICU might be at fault (or the connector). If not, the problem lies elsewhere.

If the motor turns over when you jump the tags on the starter relay and only poorly when you push the start button then the next logical move is to replace the starter relay.
I would be replacing the starter relay with a solenoid type relay from any of the Japanese bikes. That relay that is OEM from BMW is to be quite honest a piece of junk and nowhere up to the job.
The solenoid type relay has a much higher contast pressure which is what is needed to prevent the very common contact welding that we see.

Rck,  He might get the same result from a replacement relay.  You can't categorically point to the relay as the culprit until you eliminate the ICU (source of the ground signal) as a cause.  If the starter fails after the test I suggest, the relay is the next possible cause.

I agree that something more robust than the BMW relay is needed in this circuit.

robmack wrote:Rck,  He might get the same result from a replacement relay.  You can't categorically point to the relay as the culprit until you eliminate the ICU (source of the ground signal) as a cause.  If the starter fails after the test I suggest, the relay is the next possible cause.

I agree that something more robust than the BMW relay is needed in this circuit.

That has already been shown to have the earth from the ECU Rob
I clipped my meter to the battery while cranking....goes from 14.8 to 11.5 then back up to 13.6

You got a relay in mind Rick, one that would do a better job

Most Kawasakis, Hondas or many Suzukis
http://www.ebay.com.au/itm/Solenoid-Starter-Relay-KAWASAKI-NINJA-ZX-750-R-F-1987-1988-1989-1990-/190694077531?hash=item2c6640b45b:m:mF2c47g-B-gwFLTFP7osQ-g
Just do an ebay search for Kawasaki starter solenoid there are heaps. at half the price of the BMW one.

WOW....some good discussion here guys, and some good info.

I benched the injectors, and I get a solid 16ohms on each one.
They are really horrible looking however.  Rusty as F.
New ones on order just because.

Then I tested the coils.  According to that awesome guide by Bert the Frog, I should get 2.6ohms on the little contacts and 26ohms on the large ones.  Instead I get 1ohm, then it slowly increases. I stopped at 42ohms, lol....did I F something up?

Battery is sufficient. Tried a cold jump and it does the same thing.  There is a short in the cable leading to the ignition switch key cylinder, but I couldn't replicate it with a cont check...
...what is downstream of that, the relay?

Oh and thanks Rick, 

I just ordered that relay, $8 (in usa)

escodsm wrote:Then I tested the coils.  According to that awesome guide by Bert the Frog, I should get 2.6ohms on the little contacts and 26ohms on the large ones.  Instead I get 1ohm, then it slowly increases. I stopped at 42ohms, lol....did I F something up?

That reading is a bit strange to say the least, possibly a battery in the meter failing or a broken winding in the primary.
The resistance should idealy be 2.6 ohms on the primarys (12v side)but anything up to 3 would be acceptable. Even new coils will vary up to 10%.
From memory you should get around 11000 ohms on the secondaries (high tension). One more check is to see if there is any contact between any of the terminals to the laminated steel core of the coil, if you have a connection then any signal or High tension goes directly to ground and if you're lucky you will get a very poor spark but most likely nothing.
BTW which coils do you have, the early grey type or the later dark brown almost black with orange towers where the high tension leads go.
The grey coils are very poor performers and now being 30 years old they break up and leak sparks all over.

Hi Rick,  my coils are all black with a yellow BOSCH label, the post on them is black as well.  They look like the two on the left with red lettering (these are not mine):



These coils are $180 each after doing a quick search online.  Seriously?  Any replacement I could use that is cheaper?

QUESTION: On a running K bike, what happens if you try to start with the side stand down? Will the starter blip at all?
I'm trying to think of everything I can and may be forgetting Occam's Razor...(the simplest explanation is the solution)
My bike is on the center stand 99% of the time, but perhaps I have a bad switch down there and the bike thinks the side stand is down.


It's just the weirdest sound, to press the starter button and the fuel pump kicks on, the starter tur...STOP...

Ah do excuse me for the brain fart. Being a K75 you have good reliable coils I was thinking K100. AFAIK there are no switches on the stands of any K75

So the K100 coils are unreliable but the 75's are good? Strange. 
I too, forget I am on the K100 forum sometimes lol...

Did I ever mention that my ignition switch cylinder, that the key goes in, has a short?
If I touch the wiring at all, with key on I can hear the relay clicking on/off.

The bad coils are the old grey ones, the newer dark brown are quite good. I don't ever recall hearing of a K75 coil failing although it does look as though one of yours has been changed at some time.
I would be taking that ignition switch apart to clean it. There is a small grub screw to remove before the switch part comes out, it usually has a dob of green or red paint over it.
The switch may not be the problem but it isn;t working correctly so if fixed that rules it out as a possible source of the problem.
One thing I didn't ask is that when the starter goes then stops then goes again does this go on fo ages like if you hold the start button in does it continue to do it at that spacing of on-off-on-off for as long as you hold the button down and does the engine turn at all when the starter turns. I would not be concerned about welding the relay contacts as the battery does have good voltage.
Imge was saying earlier that hall sensors can cause this problem, do you have a way of testing them or a spare plate.

RicK G wrote:
One thing I didn't ask is that when the starter goes then stops then goes again does this go on fo ages like if you hold the start button in does it continue to do it at that spacing of on-off-on-off for as long as you hold the button down and does the engine turn at all when the starter turns. I would not be concerned about welding the relay contacts as the battery does have good voltage.
Imge was saying earlier that hall sensors can cause this problem, do you have a way of testing them or a spare plate.

Yes, this is the exact effect.  The fuel pump runs the entire time so long as the button is being pressed. The starter will engage the motor but it quickly stops before even one revolution.  I have turned the rear wheel by hand, plugs out, in gear and the motor is not seized. 

This is why I had thought "amperage issue" because it seems like there's not enough power to crank the motor over.  But with a cold jump from my wife's Kia it does the same thing.

It's cheap enough to just get an LED and wire up a bench test for the HES.  I will do that, and report back.

Edit: I have a video if it doing this a couple posts back....check it out here: https://youtu.be/boZ77SrVtdg

I should have checked the video out sooner but I only have a small limited download so I just tend to skip any videos.
There is a section on making a do hickey for testing the hall sensors on the portal page.
I haven't worked out how the hall sensors can cause that problem but seeing Ingapedia has said it I would believe that it happens.

When you get that low volts/amps cutting out and back in it is usually a lot faster.