2012 bike was fine until Fri, when it was hard to start in the morning. went on a long ride and was fine to stop start.
Then since yesterday it wont fire up. Ignition on, i can hear the fuel pump, press starter and just click.
I suspect no spark - thoughts?
I’ll plug in into tuneECU to see if there are any error messages later
Use a jump lead to put 12v directly onto the starter motor contact, see if it spins.
This will test your starter solenoid.
What makes you sure it’s not the battery?
9/10 times in my SMC it was the battery but I don’t remember hearing it sound like that but it was much older, agricultural model
By the way KTM won’t start must be the most common title of motorbike videos 
Starters not throwing the starter gear/clutch to engage.
Trying rocking it backwards and forwards in top gear .
Otherwise starter off and investigate
Often when the battery is low, the fuel pump will work and you’ll hear the solenoid trying to engage the starter, that’s the click. I’m not sure from the video whether I’m hearing the fuel pump whirring away or the engine turning over but not firing.
If the former, it might be a starter motor problem but by far the simplest thing to check first is to put the battery on charge and try again.
This too. I had a car that did this, click but the starter gear failed to engage on the flywheel. By sticking the car in gear and just moving it a millimetre or two by putting my foot out the door was enough to move the flywheel a fraction.
The whirring is starter motor itself in my opinion .
Battery was left on optimiser overnight and was fully charged
Starter motor fitment is model specific, how they work or don’t work is pretty much the same. If I was a gambling man I’d wager what we’re hearing here is the click of the starter motor solenoid and the starter motor spinning but not engaging. When working correctly the starter motor solenoid clicks as the start button is pressed and then pushes the starter motor armature out to engage with the flywheel, it is this engagement that appears to not be happening for whatever reason.
Take it to a dealer and they’ll rape your wallet for a new starter motor and up to 2 hours labour or follow the, mostly sound, advice above that relates to starter motors.
Interesting will try in gear and rocking
Hmm interesting… putting it in gear and rocking made it start up… Took a bit but started.
Any ideas? what the heck?
Man never had any of these KTM features with my Honda…
Ingress or build up of dirt in the starter motor dislodged, it’ll probably be fine for another 10 years now. Think how healthy your wallet is in avoiding all the pitfalls of dealer diagnostics.
Any way of cleaning that?
Only if you want to take it off, strip it down and give it an overall, if it was mine I’d leave as is. It’s not really broken so it doesn’t really need fixing 
Happy days
Being able to be charged doesn’t mean that much.
Is it holding charge (take the charger off, measure the voltage, leave overnight and measure again)?
Good thinking
some research and friendly advice on the ktm forum and it sounds like the starter freewheel is failing.
will need to get it to a mechanic as i dont have the toolset.
Your over thinking this, its not really broken it doesn’t really need fixing.
sounds broken to me! 
It’s your starter clutch, sometimes called a sprag clutch. The bit inside the case that spins the engine but doesn’t allow the engine to spin the starter motor. Not saying it’s the same problem but it was a common thing on the aprilia Vtwin engines where they wear out after too much low voltage cranking.
Putting it in gear is engaging the clutch I’m guessing and freeing it.
I made a video about my vfr750’s one that might help you understand how they work. NBW - VFR750 starter clutch disassembly - YouTube
