Satouf

Hi everyone I made a big mistake with YBR injector model basically before I got my A license I had the YBR and wanted more power like u do. I purchased a engine with the big bore fitted to it and sold my old engine. But once fitted the bike keeps jerking when ridding and idle the reve counter jumping. I know now that the big bore is not ideal for the injector models. can anyone help me or give a stupid YBR owner advice please.