Jerking when accelerating from stand still / fuel consumption high?

I have just finished a engine overhaul. A week ago-my Tazz 2E 1300 suddenly started jerking when pulling away. Once at speed she isn’t jerking as bad the Oil light on the dash is also blinking intermittently and fuel consumption is high. I am getting about 150km on 19 liters.
I read it could be
1. CO settings - what should these be
2. Blockage in the engine- how do I check/ remedy this.
3. The choke could be always open - how do we test this
4. Why are the correct carb / co settings.

Any other points to check.