Many thanks to the owner of this thread. It is helping many others including me. Also many many thanks to @Xulfiqar for sharing his knowledge especially on how to fix vacuum pipes.
I followed this thread and able to fix carb related issues on my own.
Now I am getting highly improved fuel efficiency i.e. 14.5 km/l in city without AC and 13 with AC in city. On highway I got 16 without AC..
Previously, I was getting 9 without AC in city and 11 on highways without AC.
Before fix:
1. Distributor advancer was practically not working, one pipe was missing while other one was connected to a wrong port on the carb.
- Power piston vacuum pipe was missing.
- Two vacuum ports were opened in open air.
Tweaks I have made after reading this thread,
- Followed this schematic diagram, also took help from the pictures owner shared in this thread.
Distributor advancer started working. Both connections were corrected as per the diagram. Power piston pipe installed. fixed ports that were inhaling open air.
Engine timing was corrected as per specs in the manual using timing gun.
Tappets rechecked as per specs.
Spark plug gaps were adjusted as per specs.
Mixture screw is set to 4 full turns (1 turn = 360 degree), specs says 4.23 turns.
Engine idle RPM adjusted to 950.
Apart from that I have been using 10W-40 grade engine oil, thermostat valve n automatic switching for radiator fan.
Still there are two ports I am unable to fix. @Xulfiqar, following is the diagram,
Could you please guide me, my mechanic is telling me these were used for AC idle but not sure how to setup.