[Jw73]

Good evening all!
I own a Brixton bx125 (fuel injected). I used to have a problem of it being hard to start from cold for months. I now have the opposite. It's starts first push of the button but after idling for maybe 30 secs it stalls.
After starting again, I'll ride off and it seems to bog down and lack power at certain revs. When clutch pulled in at my first junction the revs will drop and won't idle as it then stalls.

Starting it again takes me about 15 secs and I have to use lots of throttle to do this. After its started again it will run fine all the way to work when engine is warm but sometimes when warm it will stall at traffic lights if I come off the throttle too quickly after I've stopped. Not all the time though.

It's driving me mad. Could it be a valve clearance issue? Oil changed recently as well as spark plug and air filter.