footroid

A friend of mine has this older kids Beta trials bike which he imported from Japan along time ago for his kids which im going to restore for my son. Good compression and really not alot wrong with it except it has a faulty fuel tank filter which needs replacing so i would like advice as to where i can locate this part as im located in Thailand? Im not sure of the year and model of the bike as we dont have the import papers so if anyone can tell me more about this bike it would be appreciated. Knowing where i can buy new piston and rings for this bike would also be a bonus for the future. Thanks.