Those of you with pods, what do you do with the breather hose?

[hannibal]

I understand the purpose of a catch can, what's the point of a filter? Isn't the breather an outlet for blow by gases? Does it ever suck air into the valve cover?

[Steve]

The filter is merely a medium to catch the oil droplets as they pass by.

It is an effort to be a bit more responsible than I am, with my open hose.

You are correct, any movement of air will likely be going OUT, but as the engine cools,
I am sure that some will go IN as the air in the crankcase cools off and contracts.

.

[dorkburger]

I went old school on my son's 650.

I just bought a new hose (it's about 6 feet long) and cut it long enough to follow the frame down to the swingarm pivot. The hose extends an inch or so below the engine so it's in the air stream, and the end is cut at an angle to provide just a bit of suction.

I know it's not the environmentally-responsible solution, but it works.

.

Mine is similar, but uses the exhaust to pull a slight vacuumm on the engine...

[Joe H]

I understand the purpose of a catch can, what's the point of a filter? Isn't the breather an outlet for blow by gases? Does it ever suck air into the valve cover?

The breather vents both ways, piston movement causes pulses of pressure in the crank case.
From the little I know a crank case is mostly pressurized while running so it is mostly venting out, but by that very nature, at some point, it has to suck back in.

[Ray916MN]

No rings seal perfectly, so crankcases are positively pressurized by blow by.

[TxGSrider]

On my ktm powered atv, Ive got an aftermarket check valve installed in the crankcase breather that's basically a heavy duty PCV valve. It's a 500cc+ single cylinder and you can feel the air pulsing out of the valve with that big piston moving up and down. It only allows the pressure out which helps the rings seal and keeps the pressure off the seals to help prevent leaks. It works so well that after I shut off the quad it'll sometimes make a funny "growl" as the pressure equalizes. I'd think some type of automotive PCV valve would probably work pretty good on our bikes as there probably isn't near as much "pulsing" with 4 cylinders as there is with one big one. Just a thought.