So yesterday I went to Monir Mechanic, as @RehanBhatti suggested me. I went to him for the first time. He is a great and humble man. I told him all about my problem. He said your carburettor needs to be serviced again. The tiny lines in the carb are not properly cleaned. He said everything else is fine. You have purchased a Japanese carburettor, that is too great! I asked him to service it anyway. He literally put so much effort on it, cleaned everything that was even already pretty cleaned. He took around 3 hours. After that, the black smoke problem is totally solved now. I will post about the fuel consumption results in a week, as I will drive my car. Overall I am very much satisfied with his services. I was planing to take my car to "Abid Computerised Tuning" in Faisal town again, but decided to give it a week first and let check the results.
Here are the cost details:
1. Labor: He said we charged 1500 as labor for all this, but since you have come for the first time, so I will charge 1200 from you. I gave him 1500, as he put so much effort.
2. Carburettor Spray: Rs. 200
3. Carburettor gan: Rs. 20
Address:
If you are coming from Ferozpur Road to Defence Chowk at Walton Road, Just after crossing Khyaban.e.Iqbal chowk, on your right, you will find a board "Farooq Colony". Right after entring the colony, you will see Muzammil Oil Store. On the left of Oil store, there is a street. His workshop is 4th or 5th plot on the right side in the street. Or call him as you reach Muzammil Oil Store.
Here is the Google Map pin for Muzammil Oil Store:
https://www.google.com/maps/search/muzammil+oil+store+farooq+colony+walton+road+lahore/@31.47867,74.3594428,21z