Sled starts once than wont again

[Kami]

Loaded into trailer got up snowmobile wouldnt start. Changed spark plugs but getting no spark.
Come home tried starting and wouldnt so drag into shop. Tried starting and it started turned it off tried again and wont start. What can we check and how to check it??

 

[Ole Andre]

Flywheel/stator. Glued metal ring inside the flywheel/rotor that sometimes comes loose, or electical fault in the stator