F650 GS Crazy electrics cutout... Any ideas?

[Bjorn]

Hi,

F650 GS Dakar 2004, 80000 miles on the clock, big overland trip, currently in Costa Rica.

This morning, the bike started as normal. Rode 25km to petrol station, filled up, then bike didn't start anymore. This is what's happening:

1) Key in "ON" position
2) Dashboard lights come on as normal
3) Press ignition
4) One(!) "puffing" sound from somewhere between battery/handlebars, ALL dashboard lights turn off. (I think the noise comes from somewhere underneath the actual starter coil). Definitely NO ticking sound from the starter coil, and NO sound from the starter, i.e. bike is NOT cranking/turning over.
5) Key in "OFF" position: clock is set back to 0:00
6) Key in "ON" position: clock display turns off, NO dashboard lights whatsoever
7) Wait for 5-10 minutes: dashboard lights work again, i.e. back to 2)

I don't know why and how, but after 3-4 attempts (of waiting 5-10 minutes) I got the bike to start and rode back to the hostel, from which I'm now doing this posting. At the hostel, the bike turned on again as normal.
I'm a bit nervous about continuing into Nicaragua. Spare parts are probably better sourced here in Costa Rica or Panama (seen a few local F650s here).

Fuses underneath bench are all OK. I'm 100% sure it's got nothing to do with the actual starter (as it doesn't even get that far), and I don't think it's the battery either. (It's just 4000km old anyway, terminals are all well-connected).

Does anyone know what could be the problem? Main thing is: Where does that one-time "puff" noise come from? Could be a fuse blowing – but as I said: 10 minutes later it's all OK again and the dashboard lights come on...

Thanks very much for any kind of help/pointers in the right direction!!

[tmotten]

Do you have a wiring diagram with you? If not, PM me your email address and I'll send you the Haynes one. Strange it occurs at the press of the start button. You have a GS-911 or C'mon diagnostic tool? Any damage anywhere that could have damaged wiring?

[Quandary]

Hey Bjorn

Could very well be a loose connection on the starter motor/start solenoid. As you press the start button the high current through the bad connection will go pffffffffff as it arcs and then cause a very high resistance joint as in no power. try checking the connections on the starter (and the battery) just to eliminate that as a problem.

Good luck
Marty

[Dirtpig]

Second the opinion that is probably a connection at the battery. I have had the same thing happen many times on my wifes 03 F650. Make sure the connections at the terminals are really tight.

Kevan

[ptothek]

Third the opinion on the battery. I had the exact same problem last week when I broke down in Bulgaria. Bike kept cutting out, then when I went to start it, all lights on etc, press the start button and everything cut out Then when the key wasn't even in the speedo went crazy and the time reset itself to 0:00. After checking fuses, wiring looms and relays we hadn't a clue. Took it to a garage and got truely embarrasses when the mechanic just tightened the connection to the battery and it worked fine! Oh well you live and learn

[henryuk]

I was about to chip in about the battery connection being a possible problem, due to a mate's bike which broke down in Bulgaria, but I see he is here!

Hi PK, wicked trip - where are the photos??

[TurboCharger]

Originally Posted by ptothek

Third the opinion on the battery. I had the exact same problem last week when I broke down in Bulgaria. Bike kept cutting out, then when I went to start it, all lights on etc, press the start button and everything cut out Then when the key wasn't even in the speedo went crazy and the time reset itself to 0:00. After checking fuses, wiring looms and relays we hadn't a clue. Took it to a garage and got truely embarrasses when the mechanic just tightened the connection to the battery and it worked fine! Oh well you live and learn

Hi Bjorn,

Sounds very much like a loose connection to the battery.

I also think if it isn't this then possibly Regulator/Rectifier or wiring loom issue causing short circuit. IF this is the case then it's likely that your battery will be discharged or will be flat in a very short time, no matter how much riding you do.

Get your hands on a multimeter (or voltmeter) to check the Batter voltage.

If you have less than 11.8V at rest then the battery is flat and probably needs to be charged. Less than 12.2V and the battery will struggle to start the bike. Ideal Voltage for a new battery should be between 12.2V-12.6V (for AGM or Gel it's around 12.3V-12.9V).

Then start the bike, and check the voltage of the battery, while idling it should be 13.7 to 14.3V less than 13.6V and this is weak charge. NB during start up (whilst pressing ignition) the voltage should drop to around 10.6V +/-0.5.

Increase revs to around 3-4000RPM the voltage should go up to around 14.5 to 15V.

If the battery isn't in the voltage ranges then there is a problem in the charging circuit which is depleting the battery. Then check all wiring and connections. Clean terminals and check the connections to the starter and Regulator/Rectifier.

Good luck and let us know how you get along.

Safe Riding.

Cheers,

Pascal & Arja

[Tony P]

My first guess, again, is loose or inadequete battery terminal connection.

Before tighten them, take them off and clean the battery posts and connector lugs to get rid of the glaze or corrosion that develops in such circumstances. Scratching/scraping with a blade is better than nothing if you don't have a file or abrasive paper.

Have you checked acid levels if it is a 'wet' battery?

[Tom-Traveller]

Hi Bjorn

this may sounds strange, but it happenend to us .... too

Pushed the start button and all lights went dead

In the end, we had to buy a new CDI

After we checked at a BMW dealer with diagnostic plug, it says damaged CDI and we had to get a new one from Germany

So, if all search for broken cables, etc. fail ....

Good Luck
Thomas

[henryuk]

Also there is a known fault on some bikes where the wires rub through where the mount for the rear shock adjuster bolts onto the frame that apparently causes the same symptoms. BMW put a recall out on some looms for this reason...

[jkrijt]

Another week point in the electrics of the BMW F650 GS is the oil presure sensor. Sometimes they cause a shortcicuit.