Fuel system too lean: due to bad fuel your fuel system may blocked and this type of problem may come. Something you cam say that you are refuelling from the best pump of dhaka but pls remember that bd octane grade is not upto the mark. With the fuel from best pumps you may not face this problem shortly but if you use the bad fuel then problem may come instantly.
Cylinder misfire. Due to spark plug your cylinder may misfire and this problem may arise.
Low voltage of 12v battery.