Bro did you get the brakes serviced? As I did not see any cost details for brakes service.
If it had not been done ever since your ride came here, and it has been driven here for at least 5-6,000 Kms, or even more, then I would recommend to get the brakes service also done. After that, get it done at every 10,000 Kms.
I think, poor quality of fuel, i.e. Attock fuel (which has been used in the beginning) has played its role. And regarding incomplete combustion, it does not make sense to me. I am clueless, as to what could be the reason for incomplete combustion?
Did you see and check the spark plugs? What was their condition? Were their tips black, brown, or brownish black? etc.