some internet detective work
PITSTER 150 HO ENGINE BREAKDOWN lists the part number as 14210-I038-0000
Oil Filter MRX [MRX] - £4.50 : Startright,Hyosung main dealer, spares,sales,Motorcycles,Scooters, says a hf131 is the same
KN-131 - K&N Oil Filters, Oil Filter the k&n equivalent, lists...