Trying to fix up an ATV for my daughter and running into isinto.

• The wiring harness was toast when I got it, so I replaced it.
• Removed the remote feature it had.
• Replaced the carb and put the correct main + pilot jet in.
• ​​Did a valve adjustment.

ATV ran briefly. The tires were super low so it wouldn't move a whole lot with my weight on it. I planned to replace or try and clean the bed and air up the tires but hadn't got to it yet.

Ran it a few feet and it stalled on me.
Wouldn't start after that.

Have it starting now but will only run for a few seconds before stalling out. Once it does you can audibly hear air releasing from the exhaust for quite a while.

I'm at a loss as to what this could be.
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