'72 Mercedes wants to stall

I have a 1972 Mercedes 250C. This morning when I tried to start the car it did not want to stay running unless I “revved” the car. Also at slow speeds the car wants to stall or jerk esp. when I stop for lights and then again when I try to accelerate through an intersection. However, once I get on the freeway it’s fine. Any ideas?

The idle/low speed circuit in the carb is likely clogged.