So i bought my Hyo gt 125 not long ago and was investigating the rough starts every time from cold. Even whem left on choke i couldn’t warm it up enough to run properly. I discovered that it was running on one cylinder but when took for a ride and warmed up properly it was fairly fine but still backfiring and choking sometimes. So thanks to great help of Marcel i managed to find the issue. To cut long story short the pilot jet was clogged but only the one side which was the one that didin’t fire properly. Do not believe previous owners that carbs were cleaned and all that bollocks they stuff you up with. Check everything thoroughly not taking to account to what they said.
Bear in mind I am an absolute novice to motorbikes and managed to do it without giving it to garage so it’s not that difficult.