What could the issue be?

[GhostCloud]

So my buddy has a 2010 Kymco Sento 50 and it's starting to do this. He recently replaced the carb, fuel lines, and filters. It was running fine til today where it's doing this. Would it be easy to replace ourselves? I was thinking the ignition system, others said the battery but he charged the battery and it's still giving this issue.

https://www.reddit.com/r/scooters/comments/1l07akp/scoot_not_starting_now_cant_find_out_why/

Shows the video but it seems to stutter and won't start at all, that's why I thought ignition or even the starter to be honest. We don't know any good spots to post aside from reddit and found this, hoping it could be helpful!

[Iahawk]

How old is the battery? Has it been load tested (and not just checked with a multimeter?)

[Stig / Major Tom]

Running fine for days and days after your last servicing, yes??
Now won't start.
Good spark when tested against the frame?
Good, dry spark plug, and snug plug wire on the end?
Smell fuel after start attemps?
Is it a 4 sroke?..... miles since last valve adjustment?
Jump it with a known very healthy battery.
Report back.
Stig