I have a few
Carb:. TC-Motor Racing Carburetor Kit Carb Air Filter Stack Manifold Intake Pipe For 2 Stroke 47cc 49cc Mini ATV Quad Kids Dirt Pocket Bike
https://www.amazon.com/dp/B07JFZG6FV...ing=UTF8&psc=1
The kit is sold out, but look for one like this
I bought a couple engines. Most engine kits are good, though
XLJOY Big Bore Kit 44mm Cylinder for 2 Stroke 47cc 49cc Engine Pocket Bike Mini Dirt ATV
https://www.amazon.com/dp/B01N59J68J...ing=UTF8&psc=1
I also upgraded to a hydraulic brake for mountain bikes
https://www.amazon.com/dp/B08778ZXHS...HTRY6XPTXJV0V0
You need a +0 mountain bike adapter
JooFn Disc Brake Caliper Mount Adapter 0mm is Front 160mm Rear 140mm
https://www.amazon.com/dp/B07NV7DV5J...ing=UTF8&psc=1