motor goes off while driving

hi – can someone help me? I have the problem that the engine always runs out after 50 – 60km drive as if I had no benizin anymore so then I am always standing and the sporty does not start at all – only after 10 to 15 minutes of wadetime she lets herself start again and afterwards she runs forever. at least until the next time I start her cold then starts above described scenario from the beginning. I am really overwhelmed – before Christmas I was in the states and the hd dealer of the atlan tic country store told me it would be the ignition module (ignition box). however, I have already carried out a test (running at the stand and simulating artificial overheating with hot air hairdryer) and I don’t think it is. what can that be? my km stand is 54000 please help me because I want to be able to drive smoothly again in the early year from the tank or carburetor also come?