venting and breathing

[dhenry]

Hello,

My '70 998cc is running a single HS4 with a breather pipe. Up until now i've had the breather pipe blocked off but I wondered if I should put it to use. Should I connect this to the rocker cover, the crankcase breather or both? Or should I leave it blocked? Should I connect the rocker cover and the crankcase breather to the same pipe and have it run off or in to a catch can? Or should the crankcase be left on its own and the rocker cover piped into the carb? Any help would be grand. Cheers,

[InimiaD]

My bog standard MK2 998 has the rocker cover pipe connected to the standard round tin air filter box on an 1 1/4 carb. there is also a breather pipe off the back of the tappet chest cover.
Because of your carb / filter set up things are a bit different though. Have you got a breather off the timing cover.?