okay. so tomorrow i will go to a local mechanic. and get the things checked.

Even i think the solution should be to get your carb fully removed and cleaned, also the petrol tank cleaned, the petrol filter too and as said above to check the spark plugs.
I cant understand why do you keep running to the SC guys. Get a local mechanic who will do a much better job to your satisfaction.

Even i was facing misfiring problem in my yamaha. And i had my carb cleaned 3thrice. But everytime the mechanic found out little dirt particles in it. So finally he drained the full tank, had it pressure washed to remove any dirt particles from inside, then he also opened and cleaned the fuel tap, and then the carb. And now my bike is running smooth as ever. So i hope that should solve your issue. If you can go to mulund then you can meet my mechanic, His name is swami - 9867421614 and jus tell him that you are lancy's friend. Give it a try and see it, if you dont wanna keep the bike with him its okie, you can stand in front of him and he will do all the work in front of you .

My pulser 180 has the same problem after the last service. I returned the bike to them but they cannot find any problem.It runs smooth then after a few kilometers it stalls as if there is no petrol in the tanks and comes to a complete stop. After 10-15 minutes starts normally.

update-

changed the petrol. did over 150 kms after the change. did not have a single problem after the change. all is fine now. and mileage seems to be okay too.

but now i am wondering, what might have happened to the bike? was it bad petrol?