Crank seal?

[Adamleslie8]

Would a crank seal cause smoke from the exhaust and why? Had a leaky one and replaced on my kx250f and now I have smoke blowing out the exhaust like crazy.

Edited August 10, 2016 by Adamleslie8

[Kawabuggy]

*Deleted response as OP has edited his initial post*

Edited August 11, 2016 by Kawabuggy

[Confederate]

Did you just replace the left one?

[Adamleslie8]

Sorry I have a 07 kx250f 4 stroke. Yes I replaced left one behind the sprocket.

[Adamleslie8]

https://youtu.be/8CSaVW7aIc0

https://youtu.be/D6uhCaNZwsE

[Confederate]

The one behind the chain is the transmission output shaft seal and shouldn't have anything to do with the engine per say. Did you add oil after fixing the leak? Did you over fill it maybe?

[Adamleslie8]

I replaced the rings on the piston and Hobbes the cylinder as well :/ I wiped some oil on the cylinder to help install.

I checked my coolant and its full.

I filled it with oil and haven't ran long enough to see if it's losing a lot. Should I just take it for a ride for a hour and see if I lose abunch?

[Confederate]

That's an entirely different thing. It will take a bit to burn the oil and the rings will need to seat. Run it a little bit to seat everything and burn it all out. Was it smoking before you put rings in it? If so the exhaust will be full of oil also that will have to burn out.

[Adamleslie8]

Yes it was smoking a bit so I changed rings and honned but now it's smoking a ton as per video. Would I be safe in riding it and just checking oil level? Exhaust does look oily

[billygildark5007]

Oil will enter the combustion camber threw piston rings or valve seals or worn guides. Your Deffinatlety burning oil.

Did you measure your piston to cylinder clearance or cylinder for being out of round?

Unfortunately you need to dive into it again.

I wouldn't ride it until the problem is resolved, the spark plug could foul at the worst possible time.

[Adamleslie8]

This was the puddle on the piston when I took apart. Would overlapping oil expansion ring cause this?

Cheers

[Adamleslie8]

Forgot to attach pic :/

[crazyal426]

You have either a oil rings or a bad valve stem seal.  Since it is worse now since you swapped the piston and rings, I would venture to say you got an oil ring in wrong or possibly damaged.