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.

It's weird that I had the bike for a trouble-free year before the starter decided to go wild. I'll make sure the plastic is OK before I reassemble. Wondering if the battery being super strong is somehow causing things to show up.

Is there anything else I should check?

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

Check the the BMW part number against this and you'd see it's not the correct regulator for a K100. Voltage rating is not the same anyway and the design looks different to me.

BMW part #12311459286
http://www.euromotoelectrics.com/product-p/boalt-reg286.htm

To find part numbers for your model, go to...
http://www.realoem.com/bmw/select.do
and enter your vin number. Use the menus to search for the part you need

It is looking like my ignition module will be here before the brushes. Think I'm OK to throw the old brushes in and ride it for a day or two, assuming the ignition part fixes it?

The CDI unit did not fix the problem.

Edit: if it helps, now it appears to simply not start at all. Before it seemed to kinda run, nothing now.

Hi FM. That's not good.
What was the last thing you changed before it went dead? You changed the ICU?? Maybe try putting the old one back?
Did you change the alternator regulator/brushes? Did you get the correct unit?
Maybe something was not connected when you replaced everything?

I think you need to go back to basics and follow the Troubleshooting Chart on the portal page.

Firstly, what voltage are you getting across the battery with ignition off? ______
Make sure the Kill Sw is OFF and the GB is in neutral.
Do you get a green neutral light? _____
Does the starter motor turn? ______
Can you hear the fuel pump? _____
Do you have fuel pressure at the fuel rail? _____
Are the SPs wet or dry? ____
Do you have spark? _____

Work your way down these and get back.

For what its worth my son had an electrical problem. Tried everything. No good so got a replacement component that didn't fix the problem. Eventually discovered the replacement component was defective too, with the exact same defect as the original he removed.

Whatever about the problem it is essential to go one step at a time and follow the trouble shooting chart. Its not unheard of for a problem to occur after doing some job because something has been moved or slightly disconnected. Been there myself with electrical issues and am now convinced a lot of them arise from a poor/degraded electrical connection or the dislodging of a connector while doing some other maintenance.

The battery is getting killed very quickly. Not sure why. I am charging it as I am testing, though. It was at 12.7, and the starter was turning very slowly, so I'm letting it charge now.

Voltage is good, though there is about a .1V draw with ignition on. Headlight, maybe?

Starter seems to turn fine. Fuel pump cuts on as normal. Will test spark in a few, after the battery charges.. The plugs are wet- a bit of oil on them (sitting on the side stand for months), so I can't be for sure if it's gas, but I'll try again later today.

I forgot to mention- while taking apart things, I accidentally cracked the little plastic washer under the starter positive wire. I figured it was just a generic insulator and replaced it with a thick rubber washer I had handy. Can this cause any problems?

FissionMailed wrote:The battery is getting killed very quickly. Not sure why. I am charging it as I am testing, though. It was at 12.7, and the starter was turning very slowly, so I'm letting it charge now.

Voltage is good, though there is about a .1V draw with ignition on. Headlight, maybe?

Starter seems to turn fine. Fuel pump cuts on as normal. Will test spark in a few, after the battery charges.. The plugs are wet- a bit of oil on them (sitting on the side stand for months), so I can't be for sure if it's gas, but I'll try again later today.

I forgot to mention- while taking apart things, I accidentally cracked the little plastic washer under the starter positive wire. I figured it was just a generic insulator and replaced it with a thick rubber washer I had handy. Can this cause any problems?

Not a good idea to try to start with a charger attached. The vast majority of chargers aren't up to the task. Either wait till its charged or use jumper leads from a good battery/jump start unit. 

.1V draw is confusing. Draw usually refers to current, and if talking voltage, drop is used. Can you be a bit more specific?

Replacing a 'solid' plastic washer with a rubber washer would likely mean that the lead is not attached as tightly as desired, and pulling starting current may mean excessive voltage drop at the connection meaning lower voltage at the starter. Not good. 

Regards,

Bill

Sorry. 
Drop, not draw.
The charger is not attached. 
I will go out and purchase a solid plastic washer-and by the way, how is the nut/lead/black plastic washer oriented on a stock bike?

Thanks for the patience.

FissionMailed wrote:Sorry. 
Drop, not draw.    
The charger is not attached.   
I will go out and purchase a solid plastic washer-and by the way, how is the nut/lead/black plastic washer oriented on a stock bike?

Thanks for the patience.  

Plastic washer is to insulate the bolt carrying the starter current (12V) from the body of the starter motor (earth potential). Can't remember the K specifics, but either from inside the starter body, or outside or both, there is a sleeve that insulates the shaft of the bolt from the hole it passes through. Sometimes separate, sometimes part of the flat plastic washer. 
In order, starter body, plastic washer, nut, cable tab, metal washer, nut. 

Hope that helps. 

Bill

Its possible that the plastic washer is part of the brush set (#11 in the diagram).
Someone might have an old set that they could donate the washer to you if you can't pick one up.

Kaptain Holister wrote:Its possible that the plastic washer is part of the brush set (#11 in the diagram).
Someone might have an old set that they could donate the washer to you if you can't pick one up.

The brush set I bought a month or so ago came with new plasitc washers etc with the brush (#11+#13)

My work schedule is making it impossible to mess with this thing...

I got some plastic washers from Home Depot and threw those on the starter. It was enough to let me check the spark on 3/4 cylinders (so both coils are good) before the starter relay welded itself shut again. It does appear that fuel is making it to the cylinders, as the spark plugs were a bit wet.

Any idea why the relay keeps fusing together? I guess it's just too far gone, but clearly the high draw problem hasn't been solved. What kinds of problems can a too-small battery potentially hide?

A too small battery can cause the problem you are having too, just like a bigger battery with a low charge......

But it now has a properly sized and charged battery.

FissionMailed wrote:Any idea why the relay keeps fusing together? I guess it's just too far gone, but clearly the high draw problem hasn't been solved. What kinds of problems can a too-small battery potentially hide?

A small battery will not hide any problems. Not only can it cause electrical problems but it will not be able cope with problems caused by other electrical components.
The starter relay contacts fusing could be caused by excessive cranking. Bad battery. Worn starter brushes. Bad relay

I can see that this problem is going on for too long and you need to do something positive about it but its difficult for forum members to help if you don't feedback information.

Are the SPs sparking? are they wet or dry? You said you were going to check but I can't see that you've done that.

To save us having to read back thru 4 pages you'll need to let us know what's happening now.

Is your load shed relay is working properly? This could cause additional drain on the battery while starting, reducing volts to the starter relay and starter.

Cranking the starter is a big drain on the battery so keep it to a minimum. About 5 seconds at a time with a rest in between. No point cranking over and over. If it doesn't start with a couple of cranks its not going to fire up and you'll just be stressing the battery AND the relay. Keep it charged up?

Have you checked/replaced the starter brushes? You have said you "took things apart" but we've not heard what condition they were in.

Not sure what that 1V drop was you mentioned. Where did you measure that and what was on at the time?

Maybe the starter relay is not capable any more. You could try cleaning the contacts with emmery paper but I think that you need to focus on why its not firing up.

Have you got spark? Do you have fuel pressure? Are the injectors firing? These are important questions to answer.

Kaptain Holister wrote:A small battery will not hide any problems. Not only can it cause electrical problems but it will not be able cope with problems caused by other electrical components.
The starter relay contacts fusing could be caused by excessive cranking. Bad battery. Worn starter brushes. Bad relay

Are the SPs sparking? are they wet or dry? You said you were going to check but I can't see that you've done that.

Is your load shed relay is working properly? This could cause additional drain on the battery while starting, reducing volts to the starter relay and starter.

Cranking the starter is a big drain on the battery so keep it to a minimum. About 5 seconds at a time with a rest in between. No point cranking over and over. If it doesn't start with a couple of cranks its not going to fire up and you'll just be stressing the battery AND the relay. Keep it charged up?

Have you checked/replaced the starter brushes? You have said you "took things apart" but we've not heard what condition they were in.

Not sure what that 1V drop was you mentioned. Where did you measure that and what was on at the time?

Maybe the starter relay is not capable any more. You could try cleaning the contacts with emmery paper but I think that you need to focus on why its not firing up.

Have you got spark? Do you have fuel pressure? Are the injectors firing? These are important questions to answer.

Definitely not cranking excessively, only in short bursts. 

The battery is brand new, never used on a running bike, and is charged every time I mess with the bike. 

Starter brushes, I posted photos of and were told they look good.

The relay was brand new, but fused itself together the first time I used it. And the second time, even after cleaning it up with Emery paper.

The load shed relay I may not have tested, I don't recall. The lights cut off on cranking, though.

I posted earlier this page that I had spark on 3/4 plugs (them the relay failed...), so I imagine the coils are fine. Was not able to test the 4th plug die to the starter relay sticking.

Plugs are wet, all 4 appeared slightly moist and smelling of fuel. They were dried off before cranking.

Fuel pressure is a yes, at the pump and at the rail. It held pressure for a long time, too.

The 1V drop was a mistake in terminology I made. I was referring to how the starter seems to be drawing a lot of current and drains the battery quickly.

Thanks again for the help.

One thing that I think needs testing is the starter armature. It is a fair bit of stuffing around but it needs to be done if only to rule out a potential problem area. Remove the starter and disassemble it test using a meter from each segment of the commutator to the central shaft. There should be no leakage at all i.e. infinity on the meter ohms scale.
To be quite honest I am not expecting to get any reading and if there is it will be a first for me on a ND starter motor.
Also check each winding for leakage to adjacent windings. I am not entirely sure this is correct but each winding should be isolated and will be connected to its corresponding segment only. The segments will be 90° apart so put the meter on a segment (ohms scale) and probe with the other lead to find the corresponding segment and there should be a connection to only one other segment of the commutator. If you get a connection to more than one segment then the armature is cactus.
If you aren't sure take it to an auto electrician. If they say its a motorbike then immediately go elsewhere because they are stupid and not the type to be let loose with a meter.

Hey FM
Which regulator did you buy because the one you posted about was not correct. I did give you a link to the correct one.

Here are a few thing you could check.

There seemed to be a little confusion about SP leads. Are you sure you have them around the correct way. 1/4 and 2/3 ... the coils are marked.

The starter needs to earth properly to complete the circuit. A resistive connection to earth will mean lower volts, the starter will draw more current and that can weld your relay.
- Clean the base and the bed it sits on where its held down with 2 bolts.
- Also clean the GB earth connection. You have said that you didn't take this off. It corrodes badly sometimes and can be difficult to remove. A sure sign its not a good connection.
- The cracked washer on the starter connection may have already been cracked. But this needs to be replaced with the correct piece otherwise you may be getting some shorting to earth while cranking. Unless someone can send you the parts from an old unit to correctly insulate the starter B+ terminal you may have to purchase a new brush set from EME. Just replace the insulating washers and keep the brushes for next time. This could explain your battery drain. It would only short while youre cranking and the current could be arcing across the bad insulator.

You may need to verify your injectors are squirting properly. There's lots on Youtube to show you how to clean and check. You just need a 9v battery, 5cc syringe body and a can of carby cleaner.

There was something funny happening when it was running ie not revving over 2k. Your TPS is dissconnected I presume so take the FICU connector off and check there is no continuity between pin #3 and #4 or between those pins and earth. There could be a short in the loom which is confusing the FICU.

While you are there, check you are getting 12V on pin #12 when ignition on and starter pressed. This is power to the injectors.

Kaptain Holister wrote:
There was something funny happening when it was running ie not revving over 2k. Your TPS is dissconnected I presume so take the FICU connector off and check there is no continuity between pin #3 and #4 or between those pins and earth. There could be a short in the loom which is confusing the FICU.

While you are there, check you are getting 12V on pin #12 when ignition on and starter pressed. This is power to the injectors.

The FICU thing is new. So take the multimeter and measure resistance between pins 3/4, then pin 3/negative on battery, then pin 4/negative on battery, correct?

The regulator is from EME

FissionMailed wrote:

Kaptain Holister wrote:
There was something funny happening when it was running ie not revving over 2k. Your TPS is dissconnected I presume so take the FICU connector off and check there is no continuity between pin #3 and #4 or between those pins and earth. There could be a short in the loom which is confusing the FICU.

While you are there, check you are getting 12V on pin #12 when ignition on and starter pressed. This is power to the injectors.

The FICU thing is new. So take the multimeter and measure resistance between pins 3/4, then pin 3/negative on battery, then pin 4/negative on battery, correct?

The regulator is from EME

If its new to you... maybe you haven't been to the Troubleshooting Page. Would be worth reading that.

Sorry I made a mistake The TPS is connected to pins 2&3... but yes correct. doesn't have to be the neg terminal. Any part of the frame will do. There should be no connection between these wires or to earth with the TPS disconnected.
This test assumes you have good earth connections particularly the GB earth. IT MUST BE GOOD.

Also make sure you have earth connection (continuity) on pins 5 & 13 while you're there.

You're testing the plug NOT the FICU itself. Don't put the meter on the pins of the unit.
This is well explained on the troubleshooting page.