2014 KTM 450 sx crank case breather line freezing.

[Ken Climb]

Just one ride on my new setup and my line from the head cover to the bottom of the stock intake froze up. I'm guessing a little snow got by the stock filter and sock then melted and drained into the breather hose. Overnight it froze and when I fired it up oil started pumping out my head cover gasket. Curious what you guys have done to remedy this?

 

[L.Hughes]

Had the same thing happen when I had my vent hose going in to the bottom of my airbox (stupid me). I re-routed it to enter the airbox at the very top, left side, just below the seat and haven't had the problem again with many rides on it. This is on a '12 350, but it may have the same gap to run the hose in on yours.

Also, be sure you get that valve cover gasket sealed up well when you go back together, mine blew out the "half moons" and kinda ruined them.

 

[wwillf01]

On mine I but a small air filter at the end to give more volume and to have the ability to remove and dry out after deep days..


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[moto_786]

The warm moist air from the crank case breather is hiitting the cold aluminum fitting in the air boot which causes condensation which then freezes plugging the line. I've removed the crank case breather from my air boot and capped off the aluminum fitting and then re routed the cc breather so it vents on the side of the cylinder by spark plug cap. I've never had a problem with it freezing as the heat of the engine keeps it melted and free of snow I can attach some pics if anyone would like them.

 

[Yooperwoods]

Since my airbox is mostly removed I extended the breather with some clear line up under the seat with a filter on the end. I had made a low spot in the clear line and found water collecting in it. This is condensation from the engine since I know there was no snow getting up where I had the filter. Now I've got it pretty much like moto_786 does and no problems.

 

[Lachoneus]

sure bring on the pix!

Pix would help, thanks much.

 

[Throndson]

I had the same issue on my Sx-f 450 a few years ago.
My theory is its the cold air from the intake meeting the hot air from the valve cover breather will cause an ice blockage in certain conditions.
I don't have the bike any more to show pics but I simply disconnected the valve cover breather from the air boot (plugged the boot) and stuck a smaller hose into the hose and routed it over the subframe of the bike and down towards drive chain. This fixed the problem for me. Also my airbox stayed cleaner. Prior to this mod id also end up with an oily froth behind the filter most rides which id end up cleaning every ride. It was nice to not have to do that anymore.

 

[moto_786]

Here's a couple pics of how I have mine routed the pic with the pipe wraps is my FC450 the other is a Fe 501