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Valve cover leaking oil!

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yooper 8

Well-known member
Could really use some help! 2 guys riding 2016 ktm 450 sxf today in a foot of new powder at rabbit ears, very cold, tons on powder. Both bikes started leaking oil from the valve cover gaskets after all day of riding. Had to limp them back to the truck, and was worried the whole time they would run out of oil. Anyone know what would cause this? Thanks!
 
Tha ks! if we get the hose unplugged, do you think the gasket will be ok, or will it need to be replaced?
 
My dads 500exc did the same thing but we caught it early when loading the bike up in the trailer from a weekend at our cabin. Figured out it was the plugged breather tube issue. Got everything thawed out amd started bike and let it run awhile and no more leaks. Been on lots of rides since and no issue with gasket!
 
yooper 8 said:
Thanks a lot for all the help!
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I ran my breather to a T... One goes under the seat and the other down... That way you know it can breath... Make sure to cut long strips on the one that runs in the snow ...

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wwillf01 said:
I ran my breather to a T... One goes under the seat and the other down... That way you know it can breath... Make sure to cut long strips on the one that runs in the snow ...

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Yep thats how my husky is set up!!
 
Breather

Had the same problem. Blew my water pump seal pushed oil into the water. Hose was plugged. Routed hose up over the top of the eng. down behind the output sprocket no problems since. Replaced the seal no problems with the eng.
 
yooper 8 said:
Tha ks! if we get the hose unplugged, do you think the gasket will be ok, or will it need to be replaced?
Click to expand...


mine was ok,, what I did do is I took the valve cover breather hose pulled it off the air box, then wrapped it around the engine and zapped strapped up near the front of the engine, the hose now gets heated by the engine and exhaust. I can post a picture if I have some time.

I also covered the hole left in the intake where the hose plugged in with one of the rubber covers they give in the toolkit in the bike for disconnected the gas tank. Fits like a glove.
 
We did exactly that. Ran the breather hose along the block and down so it stays warm. Plugged the airbox hole. Ran them yesterday on brand new oil and filiters, with no problems and no leaks. thanks again to all for the help and great ideas.
 
Make sure the actual valve breather does not leak it's a crappy clamp... Also you could use a little Yama bond but MAKE sure it's a tiny bit so when you torque the head it does not get in your engine and dry...

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Cory, I think your leaking out of your filter on breather hose. Route that thing back to your intake like it came stock. I took the fitting from my factory boot and attached it to my snow intake. Previously it would oil mist the soft strut and front of kit. When you are free revving bike and tipping over it will release oil vapor from breather hose. I used self tapping 6mm hex head ktm screws, threaded into silicon boot and reinforced it with gasket sealant. Holds up fine. Just dont put fasteners inside intake tract.
 
wwillf01 said:
Make sure the actual valve breather does not leak it's a crappy clamp... Also you could use a little Yama bond but MAKE sure it's a tiny bit so when you torque the head it does not get in your engine and dry...

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Click to expand...

what do you mean?

and chum, how does re routing it an inch or two make a difference? itll just piss oil all over something else and not the motor that way. its for sure leaking out of that filter thats clamped onto the end. no matter whats on the end, and where its routed.. it would still leak wouldnt it?

either way, that vent line is always pressurized 100% of the time (when running) and like 25% of the time its spitting out significant drops of oil, not just a mist. more like puddles. the other day I was down to like 30% oil capacity. it needed half a liter or more on the trail. runs great otherwise though.
 
Breather

Cory, that sounds like excessive flow from that vent line. Is it possible that you have excessive blowby due to worn or otherwise damaged rings or cylinder? How does it start cold?
 
ugh. yes that is very possible. my rad fluid seems to be a tad weird too... almost dirty, could be a head gasket going too. damnit. its a thumper racing 520 big bore kit so rings and gasket isnt all that easy to get. BUT, if it were seriously damaged rings or cylinder walls, wouldnt it do it all the time? mine only seems to do it when run hard, and really really leaks when run super hard. BUT, not every time... so its real weird.

I do notice that my stator cover gets extremely hot, is that a normal thing? odd as its kinda cold out, and has snow shooting at it like 50% of the time. sure dont have problems with the motor icing up thats for sure.

cold starting it is a complete nightmare, but thats due to my battery. once it gets a boost it starts great and runs great and strong all day long. 43 hours on it now. all this winter.
 
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Could be losing you coolant pump seal... My 14 has a ton of pressure .. and my leak down is fine but I do have a turbo also..

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I have found I have to run a fan to keep a 220 temp ... Fyi I run Evans though which is a little warmer than normal coolant just without the hot spots ..

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