Fit For Silver Z190 Stems For Zongshen 190cc 2v Engine For Pit Dirt Bike Fit Smooth Operation Silver finished stems matched Fit For Zongshen Z190 two-valve horizontal pit bike engines treated construction withstands operating temperatures constant Smooth polished surface reduces friction with guides to minimize wear abnormal engine tick noise Uniform dimensional tolerance ensures alignment with seats, guides retainers Direct Fit For OEM replacement for worn bent stems, restores stable compression full engine power output