K1200S intermittent starting problem - K-Bikes.com - Excellence in Motion
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old Dec 29th, 2019, 4:15 am Thread Starter
Join Date: Aug 2019
Posts: 6
K1200S intermittent starting problem

I came back to biking in July after 25 Years and purchased a used K1200S and love the bike

Problems started about 2 weeks after purchase (1st week I rode it quite a lot and then went on holiday) On return of my weeks holiday it would not start. All seemed to be OK with pre-checks, it cranks but does not fire.
It was like this for 2 weeks until I had a local motorcycle repair shop collect the bike and took it back to their workshop
After a week he reported all was OK, they had cleaned up switch gear and interlocks. I did not think this was the reason for the fault as it was cranking but at least it was working.

All OK for a couple of weeks, did not use bike for a week and the problem came back.
Got motorcycle repair shop to collect again, they tried changing the tank with another K1200S they had in stock as thought it may be fuel pump, it still did not start but when they put my tank put on other bike it started that bike fine, so not fuel pump problem. IT was thought that the problem only arises when the bike has not been started for a few days

Still would not start so they took it to BMW motorRad, for one reason or another I had to wait 6 weeks for this, buy the time it went in, the fault had disappeared and was starting. BMW could not find the reason as they could not get it to go wrong including leaving it a few days before trying to start. Nothing showed up on the diagnostics. They recommended changing the battery which was done and got it back to me confident I would not have any further problems.

I have ridden it a couple of times a week for the last 6 weeks with no issues.
Last weekend I went for a ride in the rain and then washed the bike the day after. Straight after the wash I tried to start and same symptoms as before. Makes you think of a water in the electrics problem but this is the first time the bike had been washed since I purchased it and had not been ridden in the rain except for the the last ride. I have had the battery on trickle charge and still will not start.

Not a techie at all and do not have much tools. Just asking is there anything I can easily check before spending more money. I am hoping to take it to BMW Motorad soon as I can as I would like them to see it with the fault showing.

Any recommendations/advice will be gratefully received.
dellwinjan is offline  
Sponsored Links
post #2 of 14 (permalink) Old Dec 30th, 2019, 11:03 am
Join Date: May 2019
Posts: 28
Generally speaking, it sounds electrical. But there is no data to support a cause yet. Any chance you could find out if you are getting spark to the plugs? Gotta be air, spark, or fuel. Sounds like fuel is ok. (Do you smell any fuel smells when it won't start?)

I once had my 25-year-old 1985 K100rs die on me as I pulled up to work one day, just after having a fair amount of work done to it. Turned out to be a random failure due to age and unrelated to the recent work. The main ground wire was loose or corroded, and the whole electrical system just died as the ground failed. I also had two fuel pumps die on me on that bike - similar symptoms as it just died on me while driving along.

You might also check any fuel filter for clogging, though the symptoms don't quite add up.
phxazcraig is offline  
post #3 of 14 (permalink) Old Dec 30th, 2019, 11:54 am
Beech's Avatar
Join Date: Nov 2003
Location: , ,
Posts: 210
It only has a fuel strainer. Inspect the wiring to the cam sensor that is on the front of the engine case, low. Look for physical damage. Also inspect the wire bundles at the front of the bike, are the tye wraps too tight. Sometimes this breaks a wire inside. Wiggling while running is almost the only way to inspect this area.

Mount Vernon, WA.
tire guy, I'll mount your tires.
Beech is offline  
Sponsored Links
post #4 of 14 (permalink) Old Dec 30th, 2019, 3:13 pm Thread Starter
Join Date: Aug 2019
Posts: 6
Thank you phxazcraig and Beech for your comments and advice. With my very limited knowledge I agree with you both leaning towards an electrical problem. I did have the fairing off today to see if I could see anything obvious and wiggled wires around but may not have been the correct ones. I will do the same tomorrow more directed in the location of the Cam sensor and wiring at the front of the bike (any further pointers appreciated) I will have to wiggle whilst cranking the engine over. I think this is going to be a nightmare to find and can I cause further damage cranking the engine too much? As this has only occured when starting the bike so far, not when it has been running is there anywhere else i could be checking. All else failing I will have to try to get it to BMW whilst the fault is presenting itself so hopefully they can pick it up using diagnostic tools.
Really appreciate your comments and will keep you posted on any developments.
dellwinjan is offline  
post #5 of 14 (permalink) Old Dec 30th, 2019, 8:04 pm
Senior Member
Join Date: Sep 2008
Location: Honolulu, HI, USA
Posts: 138
Don't expect you will damage the bike by cranking too much but observe the starter motor for too-hot-to-touch.

My old K100RS had the SAME problem as above (bad ground that looked good) and it drove me nuts until I found the problem by accident. Happy camper that day!

I suggest your problem is only in a starting circuit, since your bike doesn't stop while running (as my K100RS did, to by immediate horror, in traffic, several times). Reference to a wiring diagram (where to get one?) and a functional description of energized starting circuits (again, where?) would be useful.
Honolulu is offline  
post #6 of 14 (permalink) Old Dec 30th, 2019, 11:11 pm
Beech's Avatar
Join Date: Nov 2003
Location: , ,
Posts: 210

To get to the starter wiring is a bit of a job but time for you to learn about the bike. You will have to remove the plastic, remove the fuel tank and now you can see the starter. You can follow some of the wiring to the starter relay nearby. So, get a Clymers manual and if you can afford it a BMW DVD for the bike. You will need pictures and info. Some of which will keep you out of trouble. When your down there all connections need to be opened, cleaned and put back. Scotch bright pads are good, Push together connectors benefit from just coming apart and going back together. Some spray CRC electrical cleaner is really good after mechanical work on connections. I also have some thin spray dielectric grease that seals connections to keep corrosion to a minimum. Your going to know a lot about your bike soon. And while your in there, remove the starter, open it up carefully and clean out all the dust. Use some of your electronic spray carefully, Grease the nose bushing, shaft the gear slides on and re assemble. Sounds daunting, but actually if you go slow, take pictures and notes, organize screws it all will go fine. Have some space to put your plastic parts, be low on gas or syphon some out. Bmw electric connectors have overlapping plastic to a sharp bit that locks in the overlapping bit hole. Do not bend them back too far, they will snap off. Go to harbor freight and buy a cheap oring pick set. This is just a set of sharp little probes good for stuff. You can carefully pry these nasty latches up a little and pull the two halves apart. The fuel quick connects on your tank are plastic,they can break. Push the little metal latch lever to open the latch and remove the male plug straight out. Keep the latch open when going back together as the latch can nick the oring on the connector and cause a leak. If you need more of these orings let me know I can mail you some for free. One thing to be careful of running the starter (heat was already mentioned, let cool three times longer than you run the starter or more) but if the battery gets too low it can not have enough voltage for successful work and the amps go up. This will weld the starter relay closed. Now you have to remove a battery lead to stop things... and get a new relay. Welcome to the mechanical world of bikes.

Mount Vernon, WA.
tire guy, I'll mount your tires.

Last edited by Beech; Dec 30th, 2019 at 11:34 pm.
Beech is offline  
post #7 of 14 (permalink) Old Jan 1st, 2020, 3:45 am Thread Starter
Join Date: Aug 2019
Posts: 6
Thank you for all your comments. You have talked me into having a go myself. I have ordered the manual and some of the tools you recommended. Not going to have time to do it until a couple of weeks time but will keep you posted.
dellwinjan is offline  
post #8 of 14 (permalink) Old Jan 3rd, 2020, 4:09 pm
jewilson's Avatar
Join Date: Sep 2005
Location: Plano, TX, US
Posts: 504
I had the same problem and it was the Electric Fuel Pump. If you can smell gas in you're it may be electric. My K1300S is a 2009 and it sat for about 6 months with out starting it. Found new fuel pump on Ebay and that fixed it.

Lot of luck
jewilson is offline  
post #9 of 14 (permalink) Old Jan 3rd, 2020, 11:17 pm
Beech's Avatar
Join Date: Nov 2003
Location: , ,
Posts: 210
In the past I read a post where a fellow had a failed fuel pump like this. He removed it and applied 12vdc for a second or so alternating polarity to the pump. It broke loose and because he was doing in in solvent flushed out whatever crap was gumming up the thing.

Mount Vernon, WA.
tire guy, I'll mount your tires.
Beech is offline  
post #10 of 14 (permalink) Old Jan 8th, 2020, 4:34 am
Join Date: Jan 2020
Posts: 4
Hi all,
Sorry for my poor english, I'm a frenchie !
I have a K1200S and I have the same problem than you dellwinjan ! and it'solved !
It was the crankshaft sensor ! inoperative ! I have changed it, and now, all it's OK !
I hope that my experience can help you !

Kind regards

Beech likes this.
Shivamata is offline  

k1200s, starting problem

Quick Reply

Register Now

In order to be able to post messages on the K-Bikes.com - Excellence in Motion forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome