The Yamaha Enticer is an entry-level cruiser motorcycle that was produced from 2002 to 2006 in India.
I've no idea how to comment as never heard the engine run, If yamaha service centre says its gone, then I would assume they would know.
Looks like a similar engine would fit, but you would need the electronics with it too. Sounds like it's above your knowledge though unless you know a sympathetic motorbike tinkerer nearby.