Welcome to the forum 1Q.
You have some good questions there.
First place I would look would be Kymco themselves. Kymco Parts Monster (.com), has an on line parts lookup. I'd look at the crankshaft, and engine case numbers for your machine, and the larger bore machines. If your crank, and case numbers match those of one of the bigger machines,you can up the game by getting OEM parts to install. (cylinder/head/piston/exhaust.
Kymco off road is not that big yet, and there are no aftermarket parts that I know of. I have looked a few times fr other members, and found nothing for the engines.
What type of carb is on there now? A CVK vacuum diaphragm? Those are available on Ebay at reasonable prices. Measure yours, and go up 5 or so mm's if it will fit.
