Sounds like a bad float or needle and seat assembly. Time for a rebuild.
what is the needle valve adjustment on a 125 DR
Disassemble the carburetor and replace the needle and seat, following the manufacturers assembly and adjustment recommendations.
It is in the float chamber of the carburetor.
You need a flexible flat head screwdriver. It looks like a regular screwdriver except the shaft is a tightly wound spring.
if you are sure your car has a carbuerator and not fuel injection like all newer cars,the needle would be attached to the topside of the float in the bottom of the carb, its purpose is to slow or speed up fuel flow into the carb. hope i helped, but i think that year of car may be fuel injected, firstname.lastname@example.org if you have any questions
Could be,Foreign material (dirt, rust, etc) caught in the needle and seat,Bad float,Float is out of adjustment,
That is the main jet needle valve.
Adjustment might not help. Sounds like the needle valve has to be changed. Might not be seating properly and therefor flooding the engine.
Could be that the fuel filter is clogged and not allowing sufficient fuel to pass to the carburetor; you might also check the carburetor adjustment needle(s) to see if they may have rattled toward the closed postion.
A bad, stuck or dirty float needle inside the carburetor.
The needle and seat.