Joel Murphy here, Winnemucca NV. I recently purchased a Coleman BT200X that is idling way to high and was looking for input on how to slow it down.

[Joel Murphy]

A carb replacement with adjustable idle would also work. Looks like the previous owner ground the end off the Rev limiter and shortened the spring so I replaced the spring but still idling high (to high for a 10 year old) and takes off without any throttle.
I also rebuild other mini bikes and go carts as well as old Hondas and tote goats!