Trouble Starting & Running

Keedo · 1 Trouble Starting & Running Tue Nov 14, 2023 1:10 am

Keedo

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Number of posts : 18

I just got my '87 K100RT with only 24k(ish) miles. The battery (or more) seems to be shot. Dead on arrival, the transport didn't turn off the ignition on a 12-hour drive.

It currently has (what appears to be) a Ballistic Evo2 Lithium battery. I tried jump-starting it; a strange burning smell started the first few times, and then the bike immediately started with the jump pack connected and choke on. I then let it sit running with the choke on for increased RPMs with the jump pack on for about 5-8 minutes. With the choke still on and the engine starting to gain heat, I disconnected the jump pack, and about 3 seconds later, the bike dies and had almost no electrical power.

Update: I Pulled the battery and appears to have overheated in parts. yikes.
So, I am looking for recommendations lol

Suzi Q · 2 Re: Trouble Starting & Running Tue Nov 14, 2023 3:46 am

Suzi Q

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Lithium batteries have a maximum charging voltage that must not be exceeded or the battery may be damaged and even catch fire/explode. That is why they need specific chargers.

It sounds like your starter pack might have exceeded this voltage and damaged the battery.

So, the recommendation is, if you replace it with another lithium battery, go easy with the starter pack!

Dai · 3 Re: Trouble Starting & Running Tue Nov 14, 2023 2:17 pm

Dai

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Don't replace it with another lithium battery. There are effectively two variants: the common type which I suspect you had and will detonate as soon as you put it anywhere near a motorcycle charging system and the type for which you need to take out two mortgages, but is designed specifically to deal with motorcycle charging systems. You will destroy a normal lithium battery, guaranteed. Your best bet is an AGM (advanced glass matt) such as the MotoBatt made down in Jacksonville FL.

Keedo · 4 Re: Trouble Starting & Running Tue Nov 14, 2023 2:31 pm

Keedo

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This is the one I am considering atm:

https://www.renegadebattery.com/products/power-sport-batteries/rg30l-bs-12-volt-30-amp-sealed-battery-500-ccas/

Tranberg · 5 Re: Trouble Starting & Running Tue Nov 14, 2023 3:20 pm

Tranberg

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Dai wrote:Don't replace it with another lithium battery. There are effectively two variants: the common type which I suspect you had and will detonate as soon as you put it anywhere near a motorcycle charging system and the type for which you need to take out two mortgages, but is designed specifically to deal with motorcycle charging systems. You will destroy a normal lithium battery, guaranteed. Your best bet is an AGM (advanced glass matt) such as the MotoBatt made down in Jacksonville FL.

An AGM (Absorbent Glass Mat) battery is a type of lead-acid battery in which the electrolyte (a solution of sulfuric acid) is absorbed and held in glass mats between the battery plates. Unlike traditional flooded lead-acid batteries, AGM batteries do not have a free-flowing liquid electrolyte.

Laitch · 6 Re: Trouble Starting & Running Tue Nov 14, 2023 3:41 pm

Laitch

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I had one of these that lasted nine years. cheers

I bought another two years ago because I saw no reason to push my luck for longer usage. Laughing

I put at least 6 thousand miles a season on my Brick. The Brick is put into six months of winter storage with a full tank of stabilized E10 fuel after a long ride. It is stored in a frigid, unheated shop with its battery ground cable disconnected from the transmission; I don't use a battery tender. In spring, I connect the ground cable and it starts right up.

If you don't ride as much as I but you don't let it discharge severely, and you keep it on a tender, it would probably work for you, too. Nice price, huh? Laughing

Dai · 7 Re: Trouble Starting & Running Tue Nov 14, 2023 5:05 pm

Dai

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Keedo wrote:This is the one I am considering atm:

https://www.renegadebattery.com/products/power-sport-batteries/rg30l-bs-12-volt-30-amp-sealed-battery-500-ccas/

Be sure that physically it's the same size (or almost the same size) as the OEM, otherwise you won't get the top strap on and you need that to hold the overflow tank. You have room to play with on the width, nothing on the length and a bit on the height. I'd go with Laitch's suggestion as it's tried and proven.

Keedo · 8 Re: Trouble Starting & Running Wed Nov 15, 2023 1:41 am

Keedo

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Number of posts : 18

Update:

Went to the local auto store and picked up the best battery they had in stock (fully intend on returning or keeping it for other testing) that would fit in the K100 RT. I charged it fully and installed it.

The temporary battery installed: Duralast AGM Ready-To-Ride Power Sport Battery ETX16 325 CCA
https://www.autozone.com/miscellaneous-non-automotive/power-sport-battery/p/duralast-agm-ready-to-ride-power-sport-battery-etx16-325-cca/350080_0_0?searchText=ETX16&redirectUrl=true

Battery Technology: AGM
CCA: 325A
Amp Hour: 19Ah
Voltage: 12VDC

I charged it fully and installed it. It started right up, Though the meter was reading at only 11.1 volts while idle. Then I turned it off, took out the battery, took out the previously installed battery tender hookup, disconnected the previously installed aftermarket fog lights, clamped on a new ground connector, and cleaned the ground screw surface above the shift lever.

I started it up, and now the meter reads:
12.07v at idle no choke @ 800+/- rpms
12.40v at idle w/ choke @ 1250+/- rpms

Letting the battery to sit with the tender overnight and will check again on it in the morning.

Any other suggestions to try next?

Laitch · 9 Re: Trouble Starting & Running Wed Nov 15, 2023 2:09 am

Laitch

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You seem to be describing symptoms of a faulty alternator/voltage regulator. Verify that all its connections are clean and tight. If so, you'll need to test it.

Keedo · 10 Re: Trouble Starting & Running Wed Nov 15, 2023 2:18 am

Keedo

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Laitch wrote:You seem to be describing symptoms of a faulty alternator/voltage regulator. Verify that all its connections are clean and tight. If so, you'll need to test it.

Looks like I need to open the manual and figure out how to test it them

with only 24k miles I wouldn’t have considered that, but I don’t want to rule anything out.

Point-Seven-five · 11 Re: Trouble Starting & Running Wed Nov 15, 2023 9:13 am

Point-Seven-five

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Start the engine, rev it to 3000rpm and then check the voltage at 2500rpm.

I'm not sure why, but I had one of my bikes that would not charge the battery at idle even though the battery idiot light was out. At higher rpm, the voltage went to 13.5 or higher which was plenty to keep the battery charged.

Not sure why it worked that way, the brushes were good and all the electrical connections were clean and tight.

Laitch · 12 Re: Trouble Starting & Running Wed Nov 15, 2023 10:16 am

Laitch

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Keedo wrote:Looks like I need to open the manual and figure out how to test it them

YouTube broken down in Bartlett? Laughing

Dai · 13 Re: Trouble Starting & Running Wed Nov 15, 2023 4:33 pm

Dai

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Nah. Way too far out in the boonies for teh interwebs.

Keedo · 14 Re: Trouble Starting & Running Thu Nov 16, 2023 2:22 am

Keedo

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Did some more testing. I am still measuring around 12v while running and i did another test with the negative on the terminal and positive on the alternator housing and that read around -2.5v to -2.8v.

daveyson · 15 Troublestarting Thu Nov 16, 2023 6:34 am

daveyson

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There's too much of a Voltage drop going on. I'd give the battery earth strap a wiggle and a good look over. The earth strap on mine was so tiny, an angel's fart would have melted it, I replaced it with a bigger one. I spose that might fix it.

You could have a bad earth connection. Another thing to try, run a temporary earth wire from the battery earth post to the alternator housing. The potential difference should then drop from about -2.6V to about nix. You could also move the temporary wire from the alternator to say the engine block, or a few different places to help narrow the source of the problem.

Point-Seven-five · 16 Re: Trouble Starting & Running Thu Nov 16, 2023 10:48 am

Point-Seven-five

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What is the voltage between the alternator body and the transmission case?

What is the voltage between the ground connection on the transmission and the negative terminal on the battery?

Keedo · 17 Re: Trouble Starting & Running Thu Nov 16, 2023 10:52 am

Keedo

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Thank you both for the suggestions, I will try both the new strap and the new readings today.

daveyson · 18 Trouble starting Thu Nov 16, 2023 3:39 pm

daveyson

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Something I forgot to mention (my brain is waiting for the weekend) I think you're saying that after disconnecting some of the previous two electrical modifications, the Voltage drop was reduced. It might be worth having a closer look at those, and any other modifications that might have been made to the electrical system.

92KK 84WW Olaf · 19 Re: Trouble Starting & Running Thu Nov 16, 2023 7:07 pm

92KK 84WW Olaf

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Has anyone wired permanently live USB sockets into the bike?

Keedo · 20 Re: Trouble Starting & Running Thu Nov 16, 2023 9:00 pm

Keedo

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Number of posts : 18

Tried some things:

New beefy earth strap from battery to screw above foot peg.
1,250rpm - 13.3v
900rpm - 12.1

Temp earth from terminal to alternator housing. No difference
1,250rpm - 13.3v
900rpm - 12.1

Temp earth from alternator housing to various points. No difference
1,250rpm - 13.3v
900rpm - 12.1

Voltage from + on alternator to - on block (sanded down a spot for good connection)
900rpm 0v (bouncing around .1 or .2

Voltage from Neg terminal to ground connection
1250rpm 0
900rpm bouncing around a lot but 2-4rpm

The previous owner said:

One of the toggles is the emergency flasher and the other I wired many years ago to adjust the computer for high altitude carburation . There is a resistor under the seat somewhere and once it is connected, the computer does not over rich the injection mixture when above ???? thousand feet altitude.

Keedo · 21 Re: Trouble Starting & Running Thu Nov 16, 2023 10:15 pm

Keedo

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Number of posts : 18

Update (sorry for double post)

Alternator positive cable coming out paired with negative on case, reads a steady 11.92v
Made a video
https://www.youtube.com/shorts/qTFQpSEpHtI?si=dx84Mah-Qs-9hHVb

Update:
Got carried away and ended up removing the alternator and disassembling it. As you can see the bottom stud gave me issues so it needs to be replaced haha.

Keedo · 22 Re: Trouble Starting & Running Thu Nov 16, 2023 11:38 pm

Keedo

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More pics

daveyson · 23 Trouble starting Sat Nov 18, 2023 4:14 am

daveyson

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Not happy with my previous attempt at making a point, and my phone doesn't usually show photos on first viewing for some reason.

Attempt two. With the jumper wire I thought see if the potential difference of 2.7 volts in the first photo drops to 0, ignore the different voltage at different revs. Now that I see the photo, this point is obsolete cause I think you have an auto ranging multimeter and the reading is 2.7 mV, not 2.7V, so that's no big deal.

Something that raises an eyebrow though is you say 0V between alternator positive and battery negative. Assuming at least 12 V between battery posts, and looking at the wiring diagram, this isn't possible, cause the alternator positive is connected directly to the battery positive. Unless that wire has been fried during that heating episode. That might explain why it's not charging good.

Laitch · 24 Re: Trouble Starting & Running Sat Nov 18, 2023 7:53 am

Laitch

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Keedo wrote:The previous owner said:
One of the toggles is the emergency flasher and the other I wired many years ago to adjust the computer for high altitude carburation . There is a resistor under the seat somewhere and once it is connected, the computer does not over rich the injection mixture when above ???? thousand feet altitude.

That is a legitimate modification to a device that BMW supplies for high elevation riding. If not connected to a switch, it must be activated by manual connection. No problem.

Laitch · 25 Re: Trouble Starting & Running Sat Nov 18, 2023 8:39 am

Laitch

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Keedo wrote:Did some more testing. I am still measuring around 12v while running and i did another test with the negative on the terminal and positive on the alternator housing and that read around -2.5v to -2.8v.

daveyson wrote:Now that I see the photo, this point is obsolete cause I think you have an auto ranging multimeter and the reading is 2.7 mV, not 2.7V, so that's no big deal.

daveyson's observation above raises an important point, Keedo. You should review the instruction manual of your multimeter so its functions and readings are clearly understood by you.

With so much oxidation on that alternator's parts and its overall dubious appearance, my inclination would be to replace it, but it could make an interesting restoration and learning project if you aren't riding this winter. Significant oxidation could be occurring to some extent on every electrical connection of your Brick. DeoxIT D5 is an excellent cleaner and conditioner of electronic connections. Your Brick would benefit from a thorough cleaning of all ground and plug connections using DeoxIT, including the plug connections of the ignition control unit and the fuel injection control unit.

Keedo · 26 Re: Trouble Starting & Running Wed Nov 22, 2023 9:43 pm

Keedo

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Hi all,

Did the whole DeoxIT and checked all connections. I did change the battery to one that was now in stock at my local store with a higher Ah at 26Ah. I also replaced the voltage regulator with a new one since it was only $30 total.

I did another quick set of readings.
1,500rpm 13.94v
1,250rpm 13.1v
900rpm 12v

Point-Seven-five · 27 Re: Trouble Starting & Running Wed Nov 22, 2023 11:24 pm

Point-Seven-five

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Looks like you have a healthy electrical system now!

Keedo · 28 Re: Trouble Starting & Running Wed Nov 22, 2023 11:28 pm

Keedo

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Point-Seven-five wrote:Looks like you have a healthy electrical system now!

The only concern I have still is starting. It's been in my garage during the testing at a steady 65 degrees Fahrenheit and when I start without the high idle (or choke) the battery indicator will go on and off, and have trouble keeping steady RPMs.

Also, only sitting at 12v at regular idle, wouldn't that mean I am slowing draining/killing the battery?

Point-Seven-five · 29 Re: Trouble Starting & Running Thu Nov 23, 2023 12:26 am

Point-Seven-five

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They're not supposed to sit and idle. You are supposed to start them and ride off.

If you are just running it in the garage, just set the idle to 2000 with the "choke", that will charge the battery. Because the exhaust will get pretty hot I don't think it's good to let them idle for more than five minutes without a fan blowing air over the exhaust headers.

Laitch · 30 Re: Trouble Starting & Running Thu Nov 23, 2023 8:50 am

Laitch

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Keedo wrote:Also, only sitting at 12v at regular idle, wouldn't that mean I am slowing draining/killing the battery?

Regular idle is a meaningless description. The idle speed specification is 950±50 rpm, not 900 rpm.The battery light in the instrument cluster should shut off when the engine is revved somewhere above 950 rpm and usually below 2000 rpm.

If the battery has discharged, charging it by idling wastes fuel and deposits carbon in the combustion chambers. Use your charger.

daveyson · 31 Re: Trouble Starting & Running Sat Nov 25, 2023 4:16 pm

daveyson

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Keedo wrote:
Also, only sitting at 12v at regular idle, wouldn't that mean I am slowing draining/killing the battery?

I agree, but I'm making some assumptions. I'm thinking the battery voltage at rest is let's say 12.7 V. So at idle you should be reading higher than this, but if this is with your headlight on, turn it off (or remove it temporarily) and take the reading again. I'm also guessing you haven't put the fog lights back on. Another thing to check would be the battery voltage at rest, and also at rest with the battery disconnected.

But by the sounds of things your bike could be fine but just not charge well at low revs, so maybe we can say it's okay but below average at low revs.

daveyson · 32 Re: Trouble Starting & Running Sat Nov 25, 2023 5:42 pm

daveyson

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Keedo wrote:

The previous owner said:

One of the toggles is the emergency flasher and the other I wired many years ago to adjust the computer for high altitude carburation . There is a resistor under the seat somewhere and once it is connected, the computer does not over rich the injection mixture when above ???? thousand feet altitude.

Here's an experiment you might be interested in, not sure if you could be bothered, it wouldn't be easy, and is based on a stack of assumptions.

I don't think the fuel injection computer can detect the altitude so the mixture is only altered while the switch is on, which should be done at high altitudes. From a previous thread I'm thinking this switch only alters the fuel mixture at full revs, by reducing the amount of enrichment by 10%. Since the enrichment itself is only a percentage of the overall, this might mean it's only reduced by say 1% of the overall amount of fuel. That might be difficult to detect.

So regardless of your altitude, using an exhaust analyser, and at full revs, it might run richer with the switch off, than with the switch on.

Dai · 33 Re: Trouble Starting & Running Sun Nov 26, 2023 6:54 am

Dai

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I should have looked at the photos before. The bottom brush on the regulator is very close to being toast, so there is your low voltage problem. I say this from experience (okay, a whole two alternators):

1. the lower brush is obviously shorter than the upper one
2. more importantly, it's hanging down at a greater angle than the upper one.

The two I dealt with looked identical to yours; when checked, the lower brush was a good 3mm shorter than the upper one and was pretty much just floating over the armature at low revs. As the revs go up and tiny imperfections in the roundness (!!) of the armature start beating the lower brush, it starts making better contact. The first time it happened to me, in sheer frustration I swapped in a regulator from a known good alternator (eliminates the possibility of the alternator windings being at fault). Bingo - perfect power output. So... curiosity got the better of me and I put the first regulator on the second alternator and put that alternator on the bike. Again, bingo - 'bad' voltage output.

Second time I had an alternator misbehaving in the same way and found the regulator had brushes like that I just swapped it without going any further.

Point-Seven-five · 34 Re: Trouble Starting & Running Sun Nov 26, 2023 9:50 am

Point-Seven-five

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Dia, if replacing the regulator, he is replacing the brushes as well. Is that correct? Then you are correct, the brushes were his problem.

Dai · 35 Re: Trouble Starting & Running Sun Nov 26, 2023 10:09 am

Dai

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Yes. They come as one unit.

92KK 84WW Olaf · 36 Re: Trouble Starting & Running Sun Nov 26, 2023 3:03 pm

92KK 84WW Olaf

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I bought regulators from Tills.de for less than €10. Not a bad price.

Given the age of K bikes and the fact that I have a few of them I have taken to swapping out known fail items to avoid future problems.

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1 Trouble Starting & Running Tue Nov 14, 2023 1:10 am

Keedo

2 Re: Trouble Starting & Running Tue Nov 14, 2023 3:46 am

Suzi Q

3 Re: Trouble Starting & Running Tue Nov 14, 2023 2:17 pm

Dai

4 Re: Trouble Starting & Running Tue Nov 14, 2023 2:31 pm

Keedo

5 Re: Trouble Starting & Running Tue Nov 14, 2023 3:20 pm

Tranberg

6 Re: Trouble Starting & Running Tue Nov 14, 2023 3:41 pm

Laitch

7 Re: Trouble Starting & Running Tue Nov 14, 2023 5:05 pm

Dai

8 Re: Trouble Starting & Running Wed Nov 15, 2023 1:41 am

Keedo

9 Re: Trouble Starting & Running Wed Nov 15, 2023 2:09 am

Laitch

10 Re: Trouble Starting & Running Wed Nov 15, 2023 2:18 am

Keedo

11 Re: Trouble Starting & Running Wed Nov 15, 2023 9:13 am

Point-Seven-five

12 Re: Trouble Starting & Running Wed Nov 15, 2023 10:16 am

Laitch

13 Re: Trouble Starting & Running Wed Nov 15, 2023 4:33 pm

Dai

14 Re: Trouble Starting & Running Thu Nov 16, 2023 2:22 am

Keedo

15 Troublestarting Thu Nov 16, 2023 6:34 am

daveyson

16 Re: Trouble Starting & Running Thu Nov 16, 2023 10:48 am

Point-Seven-five

17 Re: Trouble Starting & Running Thu Nov 16, 2023 10:52 am

Keedo

18 Trouble starting Thu Nov 16, 2023 3:39 pm

daveyson

19 Re: Trouble Starting & Running Thu Nov 16, 2023 7:07 pm

92KK 84WW Olaf

20 Re: Trouble Starting & Running Thu Nov 16, 2023 9:00 pm

Keedo

21 Re: Trouble Starting & Running Thu Nov 16, 2023 10:15 pm

Keedo

22 Re: Trouble Starting & Running Thu Nov 16, 2023 11:38 pm

Keedo

23 Trouble starting Sat Nov 18, 2023 4:14 am

daveyson

24 Re: Trouble Starting & Running Sat Nov 18, 2023 7:53 am

Laitch

25 Re: Trouble Starting & Running Sat Nov 18, 2023 8:39 am

Laitch

26 Re: Trouble Starting & Running Wed Nov 22, 2023 9:43 pm

Keedo

27 Re: Trouble Starting & Running Wed Nov 22, 2023 11:24 pm

Point-Seven-five

28 Re: Trouble Starting & Running Wed Nov 22, 2023 11:28 pm

Keedo

29 Re: Trouble Starting & Running Thu Nov 23, 2023 12:26 am

Point-Seven-five

30 Re: Trouble Starting & Running Thu Nov 23, 2023 8:50 am

Laitch

31 Re: Trouble Starting & Running Sat Nov 25, 2023 4:16 pm

daveyson

32 Re: Trouble Starting & Running Sat Nov 25, 2023 5:42 pm

daveyson

33 Re: Trouble Starting & Running Sun Nov 26, 2023 6:54 am

Dai

34 Re: Trouble Starting & Running Sun Nov 26, 2023 9:50 am

Point-Seven-five

35 Re: Trouble Starting & Running Sun Nov 26, 2023 10:09 am

Dai

36 Re: Trouble Starting & Running Sun Nov 26, 2023 3:03 pm

92KK 84WW Olaf

37 Re: Trouble Starting & Running

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