z 550 gt engine goes off and doesn’t start any more.

Hey, I have a little problem with my GT, hope you can help me. Have the bike only recently! A few days ago I drove with it for the first time and suddenly out of the blue it goes out (by stopping at the traffic lights). Well, it can happen, but it didn’t start again. After about 10 minutes. and a few meters to go home she ran again, but not for long. In the place she went out again simply, but this is when (easy) acceleration. Dar I checked the Vetilspiel, which also did not really fit. Yesterday city traffic, after 7 kilometers again the same game. After 15 min. she jumped again unheard of. I also looked at the candles, but they look completely normal, are also the standard candles DR 8… Now the question is what it’s like!? Whether the engine got hot or not can’t say badly. I hope you can help me!!!? Thanks in advance in greeting Kevin