[dave]

Hi bitsilly.
PVC stands for positive Crankcase Ventilation, what it does is allow the carb to draw some air from inside the engine and the breather is there to allow the air to get in. It is there because some compression will always seep past the rings and possiblty the valve guides and if this extra air is not drawn off it could blow seals. Just fitting a breather will allow it to vent but you could get oil vapour blowing through the breathers which in a short space of time will make a mess. Race engines that don't run PCV usually run the breathers into catch tanks to stop the oil getting on to the track.

......Or something like that.:thumb: