I have a 1972 122 B18.

The car has been in storage for 2 years.

I tried to start it today but wont start.
I drained all the fuel and put in 25l clean fuel, removed cleaned and replaced carburetor and put 4 new gapped plugs,
The car fires while the ignition key is turned but as soon as I release the ket it dies.

Any ideas as to what the problem may be?