i have a derbi variant sport 1987. it is so much fun to ride! i'm very new to moped's, but i love them! anyway. the spark plug hole stripped out, so my brother drilled it out, and put a heli-coil in, but that stripped out too! so i need a new cylinder head. where do i get one? and if i absolutely can't get one... i don't have the money to have it tig welded in, then drilled and tapped by a machine shop. so if i can't get a head, then i'll sell it. please help! i don't want to sell it, but i have only 100 bucks to buy a head for it.