I recently purchased a used fcrmx carb on ebay. I know not the smartest of moves, but it was one of those moments of weakness at 4am after working a 12 midnight shift. I installed the carb, in the prim. position the carb constantly overflows, in the "on" position it will only overflow when the bike is idleing on the kick stand. I removed the carb and removed the needle seat to find the o ring very dry and it is flate. See included video http://www.youtube.com/user/dbesselt#p/u/1/qIbfdDnZnzI should this o ring be round. Is it possible to pick one up from a hardware store if so what size is it.Or is it just a matter of trial and error to see what will fit. Could this have been the source of my problem. What should the float height set at. In the second video is the carb I was told it is a fcrmx 39 http://www.youtube.com/user/dbesselt#p/u/0/8EXVZhh5xds Can anyone confirm this from the video. Last and final question the vent line are old, what size are they I want to replace them. Sorry for the lame videos...I shot them with my ipod and it easier to post to utube video than it is to post picks. thanks for the help.