i got a little atv for my daughter called a Hemsim I need to jump the battery to get it started then it will run for 5 or 10 min with her on it then it will stop running when you go to start it back up it but it will not start does anyone have any idea what might be the problem

 

Sounds like the coil.

 

Look at your CDI. Is it five pin or 4 pin?

When you go to start it back up do you have to jump the battery again?

What do you have to do before it will restart again? Do you have to charge the battery? Or do you just wait some amount of time? If so, how long do you have to wait? Is this time interval always the same, or is it sort of random?

When it stalls and doesn't start again, do you have spark? Do you know how to check for spark?

 

i had a quad that did the same thing fairly recently and it was random like Lynn is pointing out. Raptorlegs' suggestion fit the problem i had. it was the coil. i replaced it and BAM! it was running again like normal.