1150GS Starting problems

[nock]

Spark is yellow / orange and the coil was brand new when fitted 6 - 8 months ago. Its definitely fuel not water.

I still think its spark related - but I either replaced or checked everything (unless I'm missing something).

 

[DrFarkoff]

I have an F650 that is as much of a pain in the arse and always has been everything says it should run perfect but it cuts out @ 40 seconds to a minute but move the throttle a micromillimetre and it will maintain 1700 to 1800 rpm all day let it go and the idle control valve should manage the tickover and it cuts out 40 seconds later

Anyway I digress what I was saying is that you seem to have sorted everything else Whilst the spark colour is not what I would expect It should be a bright blue purple and sharp and crisp Did you try boosting battery capacity by jumping form a car
NOTE Battery positive to positive BUT the negative to a clean spot on the exhaust or engine or crashbar It stops a voltage surge charging thru your bikes battery!

What happens then?

Dare I say it but did you check this?

From Here LINK

 

[nock]

Finally sorted!

It would appear that after fitting the replacement HES I either didn't quite nip up the pulley bolt tight enough (50Nm according to BMW), or my torque wrench calibration is out.

The moment I have tried to fire the bike up with the replacement HES fitted, the tin cup ('stator'? - don't know what its proper name is) that sits under the pulley (and has the tab that seats it correctly in the crank cut out) has rotated and flattened the tab allowing it to turn independently and out of sync with the crank.

I discovered what had happened when I began to remove the replacement HES intending on sending it back.

The tab was bent back into shape refitted with the bolt carefully torqued up to around 60Nm. Turned the starter and Bingo! It was the HES all along that had failed.

Thank you to all those that contributed and encouraged me - I've still saved a shed load of cash and learnt loads in the process.

 

[MattW]

I'd imagine that you either didn't line the tab up with the keyway when you fitted the 'cup' or it moved when you refitted the crankshaft pulley. It won't be caused by incorrect torque.

Regardless - you did some successful fault finding, learned some new stuff and your bike now works.

Good result