Carb?

Hi everyone! just picked up a Triumph 2000, absolutely mint,pased an MOT after being stored for 20 years. The only downside is the car pops on idle and smells rich. I have changed, Petrol, Fuel filter, Plugs, Leads, Dizzy cap.
I have cleaned carbs, I am not sure how to adjust mixture. They are Su Zenith carbs. I have even tried to follow a diagram but there is no mixture adjust screw. What can I do
Many thanks Simon