I had this problem a while ago and it only occurred very rarely and I mean extremely rarely, I just had my scooter patched up because there was some problem with the engine. Now after I got it repaired it stops every now and then, like at least twice everyday.
I took it back to the mechanic and they fixed it twice the second time they just adjusted some sort of screw, and it started fine. And the problem shows up again after like two days.
I was wondering if my mechanic had decided to replace my working part and put an old and worn out part. In the premise of fixing another problem?