Malaguti grizzly 50cc keeps dieing out
 

I got my little lad a malaguti grizzly 12 50cc for Christmas was told is was perfect lad had owed it 7 years not had a problem with it went out on it started 1st kick didn't have a problem perfect all day got it out next day every time started kept dieing then got it running then got it to field started it lad got half way round field then cut out now can't start it any ideas