When I had a similar problem a couple of years ago, it turned out to be the
ECU.
Apparently when the Digijet ECU fails, the injectors are powered open all the
time and flooding occurs when you crank it.
I found out my problem by insisting.   I replaced many things and cranked it
a lot.
Eventually it fired and ran but smoked really badly.   I then found out it
would run with the ECU disconnected.    There was so much gasoline in the
crankcase that it was coming up through the breather and getting into the
intake and allowing the engine to run.
Of course I changed the oil which by then was very high.      I then went to
borrow a known good ECU and verified my problem.   I spent a good while
looking for other problems first though.

cheers,  Steve