Vintage Cars: Mercedes W123, carburetor engine, selonoid

Question
Hi Ron, I have a 1983 Mercedes W123 200 petrol with Stromberg 175CD carburetor. Engine is fine running smoothly. Only problem I have right now is the engine shudders / judder when I turn off the ignition. Its like petrol is still going in after turn off. It judders for about 3-4 seconds. After that the engine will be turn off.

Could it be with the carburetor floating system?

Thanks
Azrul

Answer
the stromberg 175cd has a shut off selonoid on the bottom of it ( round knob looking thing)  This is the shut off for the fuel supply that is going into the carb.  These sometimes fail, or the wire breaks off that supplys the 12V  It can be unscrewed and bench tested. When you put 12v to it you should here it click.  Do not do this around the gas supply, best to take it off.  The other issue is a stuck float but you would be having starting issues as well.

The other issue could be the timing of the car .  Id start with the carb, its a common issue