Just a quick note: I called BatteryStuff, they answered (not a call center), and they are shipping me a new battery today. They didn't even want the bum one back, just asked that I recycle it somewhere. Should be here before the weekend.

Hi Fission Mailed

We are following similar tracks with different problems. I have a thread going that is trying to solve my intermittent engine cut out. I read your post and thought that is was funny how we are going through the same troubleshooting steps to find our problems. In my latest step, I also needed a new battery and bought a Scorpion SYIX30L from BatteryStuff. It was probably sitting on the same shelf next to your last one. Mine came properly charged but before i had a chance to see if it solved my problems my alternator jumped in line for attention. now I am waiting for brushes and a regulator. I also am doubtful that the battery will be the solution but do have a glimmer of hope.

It's too bad we don't live closer, we could swap out parts and maybe solve both our problems.

Your bike is not running, which sucks but at least when you get it started you will know that you fixed it. Mine is more of a tease. 

Anyway, best of luck to you.

FissionMailed wrote:Just a quick note: I called BatteryStuff, they answered (not a call center), and they are shipping me a new battery today. They didn't even want the bum one back, just asked that I recycle it somewhere. Should be here before the weekend.

well that's a win

finding a good customer relations and responsible company prepared to send you one . ...  good work !

Last update, for anyone still following this:

The new battery arrived on Friday- I was gone most of the weekend. Showed 12.6V out of the box. Put the battery on a smart charger, let it charge for a few hours, then let it sit last night not on the charger. This morning, it showed 12.81v. I installed it in the bike, tried starting for a few seconds-no luck, checked connections, tried starting again, and this time the brand new starter relay welded itself shut. The battery now shows 12.6v even.

How good are starter motor brushes? Sounds like excess current being drawn through the relay.

I don't know, I have never replaced them or checked. Is this something that is going to start while the bike is running and then cause the bike to not start?

I really can't get in to this kind of repair. I don't have a garage, I have street parking.

Is it at all relevant that this originally started happening while the bike was running fine and warming up on the kickstand?

Starter can be done street side on the K.

Did the motor turn over ok or did it sound struggling a bit?

I believe it sounded stronger, that's what I noticed. Almost like you could hear the compression.

So the relay failed not because the electromagnet part wasn't strong enough, but because too much amperage welded the contacts?

This seems a long way away from fuel pump issues. But the starter motor can cause erratic issues. So can not getting the earths a good electrical connection when replacing the battery, the negative terminal and the earth connection on to the transmission housing, near the gear lever/coils.

Removing it is not difficult and you already know how to get the battery out so it comes out for access. You need to undo the electrical connection on the starter, a 10mm nut as far as I remember. There are 2 Allen bolts to keep it in place and that's it, both easily accessible. You do have to wriggle it as you remove it rearwards, there is an O ring on it so be careful not to damage it. Its easily done at the side of the street.

Before opening the starter motor mark the ends with a screwdriver or something sharp that won't clean off on you so you put it back together the right way round. If it goes back wrong way it will run backwards and that's no good.

Have you a Clymer manual? Page 294 onwards covers it. The brushes are available and are not big money. The inner parts can be cleaned up easily but if there is wear you might need to replace. If you have doubts photograph it when you open it and post the photos.

If the starter is poor but has good current it can draw more than its supposed to when its turning over. It can turn over at normal speed but using excess current which can weld the relay. Dirt in the starter, worn brushes or worn commutator can cause that.

This bike is going to kill me.

We're beyond the fuel pump at this point, I believe. It turns over for a second or so after releasing the starter button.

edit: I will pull the starter when I get back from work- I see that it is actually pretty easy to get to. Assuming everything is in good shape mechanically (gears, etc) am I good to just order this? http://www.euromotoelectrics.com/Starter-repair-kit-for-Denso-Starter-BMW-K-p/bmw-strk007tk.htm

Does it have both brushes? I can't really tell.

Is it firing [as opposed to just turning over] when you have the starter button pressed but then cuts out after you release the button?

Not well. It will rev up a bit, but will not maintain idle. It does not die as soon as you release starter button

I went back to read the early posts and seems like it is doing the same thing as in the first posts.

Comberjohn had some issues with an immobiliser, is one fitted?

The repair kit is the one for it but I am not entirely sure its the problem. The kit is easy enough to fit and it does have the 2 brushes in it. It also seems to have the O ring. You could just take it out and have a good look and clean it and pop it back again. Next time you need it out you will do it while breakfast is cooking!

Electrical stuff with the K is frustrating but when you are sorted it gets good. I was in the same place with my K100LT and spent over 2 months battling it but it eventually came right and to be honest the experience made me stay with them because in fact there are not that many things that go wrong and as you have probably found its easy to take thing apart when you know how it all works. I also met some great guys off the forum here and without fail everyone was helpful, so much so that I wouldn't be bothered going to another kind of bike. But in doing mine I had starter out twice, first time just cleaned it up, second time did more and the starter wasn't my issue. It was the unit up under the headstock, but then more recently similar issues on a K75 were the unit under the seat, specifically the multi pin connection.

However if you have never been inside the starter for the cost of a few beers you will know your starter won't be letting you down.

You shouldn't really do this, but I did it. If it normally cuts out after you start it, what happens if you don't release the starter button? As in keep it pressed for a few seconds? This will keep fuelling the engine. If it's starting and firing then at least you know fuel pump works and engine has spark and the injectors are delivering fuel.

It does rev up and run, yes.

I have verified that all 4 plugs are getting spark, at least outside the engine (under pressure might be a different story, who knows)

I have NOT verified that the injectors are squirting at any point- no noid light or cardboard or anything.

Surely the starter is an issue, right? It immediately destroyed my BRAND NEW starter relay with a BRAND NEW battery.

That's good news the new bat has got your motor running but bad luck on the starter relay. Big pity.
You've obviously got some multiple issues going on here and its hard to say what came first. I'd take a guess that this has come about initially due to poor battery condition and possibly earth connections.
There could also be problems with your alternator.
If it were me I'd overhaul the whole system. Its not a big job but a bit of a hassle if you have to wait for parts. Take Olaf's advice on the starter motor but also do the same with the alternator imo. Its not worth the risk to ignore it.
Clean and deoxidise all connections.
Check your fuel supply system and injection system.
Clean and test your HT electrics
Read the stuff on the links off the Portal page.

I'm pulling the starter now. I see that the accessories aren't that hard to get to. 

As for the alternator...I should vgo ahead and rebuild it? What all is needed?  I see that purchasing a rectifier, the drive rubber things, and voltage regulator will run almost as much as a rebuilt one does.

Eh...  Probably some bad news.

https://i.servimg.com/u/f19/19/15/72/20/20150310.jpg

https://i.servimg.com/u/f19/19/15/72/20/20150311.jpg

Somebody has already opened up this starter (permanent marker on the housing) and I'm not sure I can clean this as it's already pretty dang clean. You guys may be able to say more about the brushes, though.

I have not posted a picture of the pinion because it is entirely unremarkable, the machining marks are still there and there is no damage whatsoever. This worries me though as I cannot clean this and it appears the copper has worn off

https://i.servimg.com/u/f19/19/15/72/20/20150312.jpg

Is the copper worn off or covered in carbon from the brushes? The copper parts should be raised with the in between mica parts in a recess.

Ehh...can't be entirely sure, but this looks about as good as it's gonna get. The recesses are (and were) free of carbon

https://i.servimg.com/u/f19/19/15/72/20/20150313.jpg

FissionMailed wrote:I'm pulling the starter now. I see that the accessories aren't that hard to get to. 

As for the alternator...I should vgo ahead and rebuild it? What all is needed?  I see that purchasing a rectifier, the drive rubber things, and voltage regulator will run almost as much as a rebuilt one does.

Open it up and check it out first.
Check the brushes are within spec
Have a look at the 'monkey nuts' (rubber things)
Check the slip rings for wear. They may need a clean.
Check it visually for any other sign of wear or failure like burnt windings etc
Unless the charging voltage is really low I doubt you'd need to replace the rectifier.

You could just get away with replacing the brushes (regulator comes attached)

PS: When you upload a photo, copy and past the middle link directly into your post

Thanks for the photo tip.

I can pull the alternator and check it out, but is that really related to this issue or is it just a long term bike ownership thing? 

Is that really enough junk on the commutator to cause the starter to pull enough juice to weld a brand new starter relay? Is that even related to my original problem of "the bike started running super badly while it was idling and now won't start at all"?

FissionMailed wrote:Ehh...can't be entirely sure, but this looks about as good as it's gonna get. The recesses are (and were) free of carbon

https://i.servimg.com/u/f19/19/15/72/20/20150313.jpg

My internet went down after I read this post but before I could respond. I used a very fine paper to clean the copper surfaces back to shiny and then cleaned off all the dust. The inside of mine had been very dusty. However when all was done it didn't make a difference but at the time the battery was quite new which would overcome some resistance. If the electrical earth paths through the starter are not clean and good the extra resistance this causes can fry the relay. Very important the earth terminals and the earth onto the gearbox tab are in good condition.

I'm a bit baffled, really. The ground to the transmission I have never touched, however, I measured close to 0 resistance (about .1 Ohm) through it to the battery on a multimeter a few weeks back.

The starter grounds could be bad, I guess, but the starter has clearly been cracked open before. There's already permanent marker on it. Is there a good way to test that? Would I multimeter between the starter housing and the transmission (the transmission itself, not the ground cable)?

DON'T polish the carbon off the commutator segments. The copper is full of microscopic pits and what you see is the carbon from the brushes filling those pits. This creates a much smoother surface and generates less wear on the brushes. By all means clean any dirt from between the segments.

Dai wrote:DON'T polish the carbon off the commutator segments.

Whoops. Too late. Hope I didn't mess anything up- I only used contact cleaner and some plastic scouring pad, though. There is zero dirt between the segments. I did not clean them, they did not need it.

When I get home I'll check resistance on the commutator plates and report what I find.

FissionMailed wrote:FissionMailed
I can pull the alternator and check it out, but is that really related to this issue or is it just a long term bike ownership thing? 

IMO yes. If the alternator brushes are worn past spec, it can affect the output voltage and mess with the current. You should be able to remove the regulator (with brushes attached) from the back of the alternator without removing the whole unit. You'll need to remove the bat tho and you may have that out already.
Cheers

I don't mind doing whatever needs done to the bike. I know it's old, I just don't want to replace everything on the bike at once to find the problem. I'll just pull the whole alternator out, not sure how much easier it really is to pull the brushes only


Does anyone believe I need new starter brushes, after seeing photos?

Pulling the regulator on the alternator is straight forward. The regulator and brushes are one unit.

I think the starter brushes are fine.

Diameter of the commutator is right at 28mm per my handy digital calipers.

Continuity seems fine. The strips are all measuring about 1 Ohm between one another and infinite resistance to the shaft.

Hope that helps.

You won't have done any damage by polishing the segments. All that will happen is the new (or old) brushes will have a short period of very slightly accelerated wear as they fill the pits in again. Nothing to worry about.

I'm not sure that the problem lies here, either. Any insight?

It does not appear that the alternator has ever been opened up, unlike the starter. I've only pulled the brushes/regulator, though.

Those brushes look stuffed to me. Anyone else?

My question is still would this possibly cause a bike with new battery, starter with good brushes, to lock up the relay somehow

Edit: I don't disagree that they look worn. But is this a maintenance thing or a repair thing?

I am tempted to ask 'what brushes'.

Some will say a wear thing and some say maintenance. There does come a point with an older machine that you will open these up and replace brushes as a preventative measure rather than waiting for them to give up. Planned maintenance is always much cheaper because you have a better chance of getting parts at the right price and doing the work at a time that suits you.

But yes I am unsure too if that would cause starter relay to weld itself, except that after quite a few attempts the battery could be dropping power and if this happens then welding the relay is the known effect.

Please don't take my questions as being hateful or anything. I am all about fixing things that need fixed to ensure reliability in the future, I'm just trying to separate things that will fix the bike from things that will ensure future health. I am willing to fix whatever necessary.

So, for a quick rundown of EVERYTHING that has happened from the day the bike died and what I've tested.

Bike starts up fine, idles, then after it warms up, begins running strangely and will not go over ~2k RPM. This is repeatable, and the bike will idle as long as you want it to, until you throttle it up, at which point the fuel pump and RPM jump around very erratically and the bike dies shortly after. The bike does produce a small amount of white smoke when revving it up. It even starts the next day no problem.

I throw on Bosch spark plugs (old ones were Champion) and a new FPR. I verify they spark by grounding them to the head and plugging them into the wires. At this point, the bike fails to idle any more. A buddy looks at it and he can't find anything. I let another buddy look at it and he notes that the plug wires are swapped over (not sure who did this, probably me). They are put back on their correct places. Now...here is where I get a little confused. I don't quite remember at which point the bike totally ceases to run, if it was before the wires were swapped or after.

I bring the bike back home. I test the fuel pressure at the pump and FPR, both are fine. Tested resistance on the injectors- 1 thru 3 are 16 or 16.1 Ohms, #4 tests at 17. I test the Hall Effect Sender using a 12V LED, it works fine. I test the AFM and it is definitely in pretty bad shape- I replace this with a used one that tests good. I have never removed the water temp sensor, however, I've periodically tested it from single digit temperatures to 80* (fun weather here) and it matches the chart in the manual pretty well.

All connections are cleaned with DeOxIt, nothing visibly bad is seen.

I pull out the multimeter and, beyond a few somewhat low voltage readings, everything seems more or less OK. I pull the starter relay and half a contact is missing. I replace it and the battery. The battery is fully charged. I try to start the bike at this point, and on the second try it welds the starter relay closed.

I then pull the starter and the alternator brushes, giving you the photos you have today.

Starter relay: half a contact is missing. As in one of the pins projecting from it?

92KK 84WW Olaf wrote:Starter relay: half a contact is missing. As in one of the pins projecting from it?

That was why I originally replaced it. Half of the little circular contact on the arm just fell off. The new one was immediately fried, as apparently the starter is now drawing enough current to weld the relay. The old battery was 18AH and unlisted CCA, new is 30AH/280CCA

Dai wrote:Those brushes look stuffed to me. Anyone else?

+1
5mm out of the holder is the limit. They will be touching the slip rings but no pressure on them. This causes arcing and that will eventually erode the brush away so that it doesn't even touch.

Okay... I'm going to suggest something which on the face of it is totally counter-intuitive. Take the airbox to pieces and check that the plug is secure on the AFM. I have had mine come off for no apparent reason and after a few violent hiccups the bike died completely. Not the same sequence of events as yours but if the connector was partly off and is now completely off, the bike will not start. The connector is supposed to be secured by a locking clip but I found that only partly attached.

Getting at the plug on the AFM to reconnect it pissed me off big time because there's so little room and loom flex to work with. So much so that I took a pair of wire cutters to the wiring loom and fitted a four-way block to the AFM lead. It makes playing with the airbox so much simpler.

Is this the correct part # for the brushes? http://ecatalog.wilsonautoelectric.com/index.php/62-15-6635.html

Secondly, I can check the AFM plug tonight, but being that I've already pulled the old one and thrown a new one on, I doubt the connection is the problem.

edit: So I order the brushes/regulator, then what? Try to start the bike up? Is there anything else I need to take a look at that you guys think of?

also I totally second that emotion re: removing the AFM, it about killed me. Go buy a $5 set of picks, you'll never regret it.

FissionMailed wrote:

92KK 84WW Olaf wrote:Starter relay: half a contact is missing. As in one of the pins projecting from it?

That was why I originally replaced it. Half of the little circular contact on the arm just fell off. The new one was immediately fried, as apparently the starter is now drawing enough current to weld the relay. The old battery was 18AH and unlisted CCA, new is 30AH/280CCA

My reason for asking this was...is it possible the broken part is stuck in the plug the relay plugs into or that there's a poor electrical connection in there, creating an increased resistance needing more current and frying the new relay in the process?

Also, I agree with Dai too, sometimes you have to go against intuition. When I had my problem with the LT everything at the time pointed to something other than what eventually solved the problem for me. I also feel a lot of the problems come from the connectors rather than components, exactly as Dai has said.

The more I read here the more I am convinced that the ICU is the problem.
Can anybody here explain what the purpose of the 12v power being supplied to terminal 6 of the ICU is when the starter button is pressed. It has a power supply via terminal 10 all the time the kill switch is on so why have a power supply when the starter button is pressed.
Has the TPS been tested because I have heard somewhere (I cant find where ATM) that if the TPS is disconnected then the engine will run but wont rev past about 2000rpm.

The TPS I am not sure how to test, but I have left it disconnected since it started not running.

I like the ICU idea. The only problem is that it still delivers spark-  that said, even when it did idle (when this problem started), it was clear that it wasn't running at 100%. Partial failure seems odd, but maybe that's the case.

The old relay failed internally (if you wanna call it failure-it never stuck closed-i just opened it up to check since I was doing that with everything else). No prongs were missing externally. I believe that somehow the old battery, which was too small and very low capacity, was masking some issue.

RicK G wrote:The more I read here the more I am convinced that the ICU is the problem.
Can anybody here explain what the purpose of the 12v power being supplied to terminal 6 of the ICU is when the starter button is pressed. It has a power supply via terminal 10 all the time the kill switch is on so why have a power supply when the starter button is pressed.

Rick, I believe it is just a signal to the ICU that the button is pressed; it's not another source of 12V power to run internal electronics.

the start button has two purposes. One is to start the ignition process from the ICU's perspective during cranking. The other is to enrichen the mixture when the engine is running. We use the second feature as a Poor Man's CO tester.

When I give it some more thought it is probably to signal the ICU to send the earth for the FI relay and get the pump running before pulses are received from a Hall sensor to keep the process running (makes for a quicker start) which leads to more evidence the ICU is the problem in that it isn't putting that earth there when signals are received from Hall sensors despite still firing the ignition.

RicK G wrote:When I give it some more thought it is probably to signal the ICU to send the earth for the FI relay and get the pump running before pulses are received from a Hall sensor to keep the process running (makes for a quicker start) which leads to more evidence the ICU is the problem in that it isn't putting that earth there when signals are received from Hall sensors despite still firing the ignition.

That makes sense because that signal is needed to keep the engine running. But the signal can be lost between the Hall sensor and the ICU through a bad plug connection. Or the ICU itself. Some of the tests you have done seem to rule it out but if the engine fires when the starter button is pressed it suggests everything else is working.

I'm in agreement with the ICU suggestion. It's odd, but I was kinda leaning that way after I tested the Hall effect sensor and it was OK. The tach bumping around made me think that might be the issue. I'll go ahead and order one this week.

I will also order new alternator brushes. But I'd still like to know where I should be looking for the starter issue. The brushes are fine, I'm not sure where the excess draw would come from.

Check the connection bolt where it goes through the case if it is not aligned correctly it can short direct to the outer case and FIZZ SPLAT.