There are lots of threads on forums discussing pierburg 2e3 carb failures those of which are solved either by replacing fuel lines, autochoke mechanism or totally replacing it with a weber but I can't find an exact solution pointing what causes failures and how to fix them, most of the times solution is just a coincidence.

 

In case of mine causes are clogged fuel filter + fuel vapour seperator + cracked accelerator pump diaphgram. LT starts fine and runs normally until auto choke comes down and then engine begins to stall, refuses to start, hesitates to rev, looses power etc. and one can smell unburnt gasoline. You can restart the engine if you wait for a few minutes and let the fuel pump run for a while without starting the engine but you have to rev it up and it stalls again. When everything cools down the process restarts as usual.

 

Clogged filter and swirl pot limits fuel supply as expected but even some fuel reaches the carb most of it is lost through the accelerator pump housing which I think also drains the fuel reservoir somehow. When the engine is hot it's not very easy to detect leaks because fuel almost instantly evaporizes. Also checking spark plugs and etc. doesn't help very much. In my case the crack in the diaphgram got bigger and bigger so that I can see fuel draining  and I realised my fuel filter is transparent eventhough it looks totally brown.

 

Hope this helps others.

 

Cheers