The cyl. is probably egged out so a re bore and oversize piston would be best!
Not required, I have a new stock piston and rings in a smoked cyl. you could fit a nickel inbetween the piston and cyl. wall. It runs fine. It won't last long. There are degrees of working. A 2 stroke by design eggs out the cyl. after time. Go up and down and front to back a couple million times and you get egged out.
A rebore and over size piston with gaskets and all is about $160 from a mail order joint on Ebay. About a buck sixty and you get back bolt on parts all new and machined.
I had the new piston on hand and knew I could make it go bang and wante to trouble shoot the whole system.
I would not suggest spending the time, money and effort without truing the cyl.
The ol' square peg in a round hole thing. In this case a round plug in an egged hole.
A