Crankcase breather

needpowder

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• Nov 16, 2017

• #1

My mechanic decided to do this for me when he installed my new top end. Its a k&n filter on my breather hose. Before i had the stock piece zip tied in there facing down. The stock piece doesn’t have any filter (unless i lost it). I’m sure it got some snow in it last season seeing how the airbox always has some snow getting in. No running problems though. I was more worried about it freezing up/clogging and blowing a seal.
Not sure if this filter is a good idea or not. Obviously it’s going to be covered in snow right there or anywhere else i try to move it. There’s no kinks in it or upside down “U” where water can collect. What do u guys think?
Second picture is stock piece.

 

P

powdermuncher

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Nov 28, 2007

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• Nov 16, 2017

• #2

I always ran my breather with a metal screen filter out of a snowmobile tank ( Old school ) right on top of the cylinder head behind the rad , never any snow or ice accumulating and never had water in the oil issues either.

 

T

terrancehamrick

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Nov 24, 2016

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• Nov 16, 2017

• #3

Dang, mine just dumps on the left side by the skid plate on my kx. I've never thought about getting snow/water in it. Should i consider putting a filter on the end of it?

 

needpowder

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• Nov 16, 2017

• #4

terrancehamrick said:

Dang, mine just dumps on the left side by the skid plate on my kx. I've never thought about getting snow/water in it. Should i consider putting a filter on the end of it?

Click to expand...

I dont think its a huge concern with bikes that are routed like that. My thinking is with the yz gravity is working against me. I’ll probably just put some flo right material over the top and leave it. Im just worried that stuff won’t be able to escape with the filter on.

 

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AZ800

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• Nov 16, 2017

• #5

I've thought about this. Figured a filter could ice up easier. I just re routed my case vent from dumping out by the skid plate to back up where it doesn't get snow packed around it much.
No problems in snorkel powder yet.

 

D

dooman92

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• Nov 17, 2017

• #6

Breather

Need power, I have fx as well. I left it open as you had last year. No issues. I thought about filter as well but decided on open cause of potential freezing. Probably work good with filter as it is warm most of the time there.

How did the old parts, piston, cylinder, pin and valves look when disassembled?

Any run time on pr2?

 

L

L.Hughes

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• Nov 17, 2017

• #7

I had to re-route the breather on my wife’s KTM 350 last year after it blew the half-moon our on the valve cover gasket. Just enough heat/snow/water made it freeze up. Routed it to the top of the air box, never had an issue after that.

 

Hawkster

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• Nov 17, 2017

• #8

L.Hughes said:

I had to re-route the breather on my wife’s KTM 350 last year after it blew the half-moon our on the valve cover gasket. Just enough heat/snow/water made it freeze up. Routed it to the top of the air box, never had an issue after that.

Click to expand...

Out of curiosity did you know what the thermometer was when that happened ?

 

needpowder

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• Nov 17, 2017

• #9

dooman92 said:

Need power, I have fx as well. I left it open as you had last year. No issues. I thought about filter as well but decided on open cause of potential freezing. Probably work good with filter as it is warm most of the time there.

How did the old parts, piston, cylinder, pin and valves look when disassembled?

Any run time on pr2?

Click to expand...

Nice. I’m thinking now I’m gonna go back to open but might put a wide prefilter around it to limit snow going in.

Cylinder,piston,etc looked real good. Actually my mechanic buddy is installing it in another fx that has become “loud” after he ingested water in it. As trade i get some free sprinkler work?

No run time yet on pr2. Haven’t even fired bike up with it but i did hear the fuel pump kick on as soon as i plugged it in. After that I disconnected the battery until i ride it. Hopefully tomorrow on the road for break in?

 

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L.Hughes

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• Nov 17, 2017

• #10

Hawkster said:

Out of curiosity did you know what the thermometer was when that happened ?

Click to expand...

Not exactly, although it was right around Christmas and from memory I’d say it was 15-25 deg. F

 

needpowder

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• Nov 18, 2017

• #11

Went back to open like it was last year. Why fix what isn’t broke right?
Did a couple break in cycles this morning. Snow was way better than I thought it was gonna be. Constant face shots on the side of the road. Had to run my radiator covers to keep the temperature above 145. This with pst and foam around the engine already. Plus thermobob of course. Bike ran well with pr2. Started instantly everytime except first time because it was 9 degrees this morning so it took a couple seconds. It was trying to fire right away though. So stoked to be riding again!!