RE: help with big bore kit
you must have some kind of mark on the top of the piston, I know that CY’s big bore kits have “dot” on the piston rather than the arrow, this dot \ arrow or any other mark that you have must face the exhaust port, otherwise you might ruin the kit, also make sure that the ring is closed well around the small pin if it won’t be like that so you might ruin the head & piston.
With a basic search on that topic in the forum you will find a lot of threads, many guys had the same issue…
Good luck!