Electronics » Starting Problems.

Hello , Hopefully someone here can help me on this. My bike is a 2019 R1250RS with 11600 miles on, serviced every year by main dealer. The bike is stored in a dry garage, used only in the dry weather.

Just recently the bike is behaving like the battery in on its way out, it will start first time, but after the 3rd or 4th time , it will struggle to turnover. On occasions the TFT screen will
dim or not light up at all, but then it will fire up as if nothing is wrong.

Sometimes when it is trying to fire up, I get erroneous messages, like front indicator not working, tip sensor error, brake light not working.

I changed the battery as a precaution, no improvement. Did a parasitic current draw test, nothing unusual, like .3ma.

I looked at the earth connection to the starter, it is as new, corrosion free and tight. I am at a loss really, so if anyone has any idea on what it could be or what to check to, that would be great. Many thanks Simon.

I, and several others at the same time had that problem. It was 3 years ago. For me it happened after I stopped for petrol on my ride to work. Motor was hot. The motor would try to turn over, but just could not have a full crank.

The RS was 3.5 years old, but my dealer accepted the repair at no cost.


They did not tell me much about the solution except they said the tightened the valve clearances. The theory was the inbuilt decompression was not working well enough.

The repair was effective and I bet there is a BMW TSB for the repair.

I had a similar starting problem. even after starting, it would sometimes stall. I also thouigh it was maybe the 9 year old lithium battery, so changed to no avail. When it did this i started to get amber triangle engine light on dash. Finally checking gs911 identified various random elecltrical faults, but every time there was one common fault. 'CANNOT DETECT CAMSHAFT EDGE POSITION' Some reserarch led me to change the camshaft position sensor under the left cam cover. £50 part. Problem resolved. worth considering if you have access to gs 911 and nothing else is found....

"struggle to turnover" is an important clue. This points to a battery, cable or starter problem. Even though the battery is new, have it load tested. Many auto parts stores will do this for free. If the battery is good, then it could be a bad starter, loose cable at starter, starter relay. Check the ground cable from the battery to the frame.
Grab a multimeter and test your battery and charging system. It's simple to do. Do a search with "how test a motorcycle battery and charging system".

Hi @simonjohn
Did you find the answer?

I'm in Sydney Australia with a lazy 2019 R1250RS like yours.

I bought my bike in May from a private seller. Super excited to have my dream bike after oogling them from my Honda since the R1200RS was released.

Unfortunately, on the third ride, my shiny new toy did what you describe and now, some months later, she won't start at all.
BUT, I am not getting any continual engine lights or error messages (I kind of remember getting one about traction control or something similar but at the time I assumed it was due to a low battery. Hmmm)

The long story:
On that first fateful day, she started fine cold... But when I stopped 20mins down the road to visit a mate, she decided she wouldn't start again - I had no idea she was telling me that she was ill.
(My mate had a steep driveway, so after a long push up the hill, I clutch started her fine that time.)
I thought I'd left the lights on or something so I went home.

The next day I wired up connections for a trickle charger on the battery and plugged her in.

A week later, I jumped on her again - full battery - should be good. An hour later, I stopped at my destination and she wouldn't start again. (no hills nearby this time) after 10 mins of wondering what to do, I hit the starter again and she turned over, but only just.
I figured the battery must be done, so I bought a new one.

Next ride, she started first time but after a break, she wouldn't start no matter what I did, so I had to buy a jump start kit, which helped her kick no problems.

Since, I haven't been able to start her even with a full battery and the jump starter connected.

Time to investigate with help from ChatGPT and my electrician's multimeter:
- I checked for voltage leaks, as I had installed a wireless charging quadlock and the trickle charger. - No issue with those.
- Alternator was fine - getting 14.4v while riding.
- I fully charged both the old and the new battery - hold 12.9v and 13.1v respectively after sitting unplugged on the bench for a week.
- Standby voltage 12.97v (electronics on, engine off)
- parasitic amp drain when in sleep mode ~ max 4.0mA (normal)
- phone charger separately - ~0.2mA (fkall - can rest with this for 3 months without affecting battery)

Cranking Test with full battery
- First start - Voltage drops during crank to 9.9v - struggles to turnover
- Subsequent tries - sags to 5.5v

Starter circuit tests
- Wiring and connections all in good condition - corrosion free
- Positive side voltage drop (from battery to starter rely): ~8.6 mV (excellent).
- Ground side voltage drop (from battery to engine casing): ~147 mV (excellent).
Confirms cables and ground strap are sound.

I fear a spent starter motor or computer - Might try Wessie's suggestion:

Zitat

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I would check the main plug to the ECU. Unclip it and check the pins for corrosion. Same with the power module.

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I had a similar issue some years ago with my year-old (at the time) 2007 R1200R. Even a jump start from a car, wouldn't keep it running once the jumper was removed. It turned out to be a defective BMW-brand battery, which was replaced by my dealer under BMW's 2-year battery warranty. Once the battery was replaced, I never had another starting problem. Sometimes motorcycle batteries just go bad and develop an internal short. They will show a normal voltage when fully charged but when placed under a high electrical load like starting, they just crap-out. Before getting too crazy replacing expensive parts, first try replacing your battery with a new one that has been fully charged on a battery maintainer. New batteries and clean, tight battery cables usually can solve most electrical problems. But if that doesn't work, it might be a wise thing to do to have a dealer diagnose the problem. I sounds like you have gone about as far as you can go in your garage.

I’m chuckling tonight from the comfort of a hotel room. No bike involved.

Because, last Friday morning my trusty steed failed to start at the second start of the day. After only 8 miles.

I called rescue man who told me the battery is in good condition. Suggested dirty cable connections may be the problem. I’ve yet to remove the battery and check all main cable connections.

After firing up I rode home non stop for 200 miles in 4.1/2 hours. Luckily my bike is all day comfortable.

The “other forum” just had a useful thread on step by step checking of starter system possible faults.

Battery. Solenoid. Starter motor. Starter button. Clutch switch. Side stand switch.

One other thing to consider is the maintainer ... I just had this problem on my 2016 Canyon. Some maintainers don't recognize (think cheap) the battery if it is bellow a certain voltage. And in my case, I had the maintainer on and it claimed everything was fine. Even after I couldn't start the truck the first time I put it back on and it claimed to be charging, and in fact finished the initial charging and then showed the fully charged lights like it always does. Problem was the battery was deeply discharged and wouldn't even crank the truck, still. It took about three days with my old 1970s charger to get the battery back up some what (one of those giant optima batteries). And I shit canned the trickle charger/maintainer that wasn't even seeing the battery it seems.
So my BMWs are on Optimate 4 chargers, and they are very good maintainers. So I needed to have a charger for deeply discharged stuff, as the 70-s charger is getting long in the tooth. And I needed a maintainer for the truck, so I bought the optimate 7 (10+ amps) for the truck and it finished up the charge and everything is fine.
One important thing to consider is the Optimate chargers I have monitor the battery and only charge it if it needs it. You can see them go back to charging for a minute, by the indicator lights. The other big thing is these chargers come back on after a power interruption, exactly the way you had them set. The charger I quit using, had to ask if the bat was lithium or lead. It would not come back on with out input from the operator .... The line are killing the power around here a fair amount so that old maintainer was probably screwing up a lot And I didn't even know it ....

Maintainers monitor voltage and not capacity. You can have a battery with a nominal voltage but below tolerance capacity If a battery has a sulfated cell that causes 2 plates to short together., the maintainer will display as a fully charged battery but the battery will have very low capacity. Some maintainers have a de-sulfate mode but if a battery has been sitting with a very low charge level for too long, the maintainer will not be able to force all of the sulfate back into solution. A very low charged battery that sits for too long will always have lower capacity that cannot be resurrected.
The de-sulfate mode works by increasing the charge voltage above the normal charge voltage. This is why you should never use a maintainer with a de-sulfate mode on a Lithium battery.
Some of the cheap maintainers don't monitor voltage and just apply a low amperage charge at all times. This is why you should not leave a cheap maintainer on your battery for long periods of time.

Zitat von dravnx im Beitrag #11

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If a battery has a sulfated cell that causes 2 plates to short together., the maintainer will display as a fully charged battery but the battery will have very low capacity.

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