Crankcase breather

[rerb]

With the use of the turbo feeding oil back into the sump, is an extra crankcase breather a requirement? I see a few that replace the oil fill cap on the clutch cover, but they're close to $150 with shipping. Curious if anyone runs without one, aiming for low boost (~10 psi) for at least a month or two before cranking it up. 

When I first disassembled the bike, I removed a capped off hose and labeled it "crankcase" However, a few months later when putting it all together I can't find where the hell it cam off from, if it does attach to the cases, would uncapping it and using a filter work too? attached is a photo of it off the internet. Mine was capped where the smaller clamp sits. Thanks.

Note, it is not the breather from the top of the valve cover. 

Edited May 29, 2021 by rerb

[Paulm]

I run two An8 breathers from the clutch cover on mine

[Gixer1460]

I used to run 10psi with old skool suck through and used the std cam cover breather tower, an additional dash 10 out of the cam cover, a dash 10 from centre of clutch cover and a dash 8 out of the filler fitting - all to a vented recirc catch tank except the dash 8 that went to a open catch bottle. Too much? Maybe, but it didn't smoke or leak oil through gaskets!

[rerb]

13 hours ago, Gixer1460 said:

I used to run 10psi with old skool suck through and used the std cam cover breather tower, an additional dash 10 out of the cam cover, a dash 10 from centre of clutch cover and a dash 8 out of the filler fitting - all to a vented recirc catch tank except the dash 8 that went to a open catch bottle. Too much? Maybe, but it didn't smoke or leak oil through gaskets!

Wow, taking no chances there. That makes sense, as far as your custom fittings went, was it as simple as drilling/tapping the cam and clutch cover? or did you have to weld in the fittings? And is the catch can necessary, or will a filter on the end of the hose work, as that's what I see a lot of. Thanks

[Reinhoud]

Think before you make a breather somewhere, when you do it on the wrong spot it can throw out a lot of oil!! Learnt that the hard way..

[rerb]

3 hours ago, Reinhoud said:

Think before you make a breather somewhere, when you do it on the wrong spot it can throw out a lot of oil!! Learnt that the hard way..

I bet, im just going with the clutch screw breather for now. The proboost kit doesnt mention a breather, and its gravity drain (for now) so I think i'm set with just that breather.