I had the same problem with mine. After lots of parts swapping between two of the three I found it to be the starter. the brushes were so worn that the engine wouldnt turn over fast enough to create a spark. This same problem then happened to a friend of mine. I pulled the starter apart, changed the brushes, part # 21039-3702 from Kawasaki,(I bought a spare set in case of discontinue). Put the field winding in a lathe and gently used a draw file to clean the brushes contact area. Re-installed the starter and she turned over like a sewing machine. Beautiful blue spark
and then it flashed right up.
Hope this helps.
