i have 2003 hyosung (alphasport/classic cruiser) 250cc. when i first bought it (3rd owner) 3 years ago i installed a stage II performance kit... thinking this might´ve caused a problem - developed a knock in the front last season; finally got it tore down to see the problem: need to replace pistons and other things relative... the guy that´s working on it suggests an oversized (0.5-1.0mm) since the performance was increased from stock, he´s also partial to ´wiseco´ brand. does anyone have any suggestions and names of stores i can check out?