Eto yung cast iron part ng carburetor, right below ng aluminum floater tank at injector. Had that same experience before sa boxtype ko, nung sinubukan kong baklasin wala akong nakitang seals, I guess lumuwag na yung shaft casing (yung naghohold ng throttle valve) due to wear. Nagtanong tanong ako sa shops and they recommended na either bago o surplus. Swerte nakakuha ako ng surplus (yun throttle body lang na cast iron) sa may evangelista, mga 450 pa bili ko nuon. Pero that was way back 2006 pa