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06 kxf 250 smoking

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I recently put a new top end in my bike, including a new piston cylinder. I also did valve seals and lapped my valves (reusing the old head). Problem is that when I start my bike it smokes a fair amount until the engine has warmed up. The smoke is a lighter color almost light grey I would say. any suggestions?

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blue = oil

white = water

black = fuel.

grey could be a water/oil mix. I would say you probably have a bad head gasket or you didn't torque the head right.. There is also the possibility your wrings are on wrong.

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you're not. How ever lapped valves will not cause smoke issues. If you have SS valve I think you can have those lapped..

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Did you just rebuild it? Could it be just excess oil from the rebuild?

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It sounds like oil burning, did you get your oil rings set right, typically the gaps are 90 degrees from the next, the corrogated oil ring isn't overlapped is it? Perhaps the rings need to seat, you hear many people complain about oil leaking out the vent after rebuild, once the rings seat they quit.

I personally have never had one smoke after a rebuild, hmmm, maybe the valve stem seals are leaking, allowing oil to pass through the valve guides into the intake and exhaust tracts. Don't ever lap titanium valves.

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I'm positive I have all the rings on the piston correctly. I have done prob 15 rebuilds on similar 4 stroke bikes. It's just the first time I've had this problem tho. I put new valve seals on the bike. The exhaust valves looked like they could have been a lil worn. I could actually only see 2 angles. Would I be nuts to just put new valves and another set of valve seals on my old head?

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Nope.. Maybe you might want to consider changing the head gasket also. I'd double cheack the rings also while you have it apart.. If you do all that. I'm sure that would probably clear up your problem..

Err.... Brain fart.. While you have it apart mic the cylinder. Maybe you have a worn spot allowing blowby

By the way what part of this glorious state do you reside in?

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I've tried two sets of rings, two head gaskets, and a new cylinder. They all gave me the same result. I'm just a hate to fork out $250 for 4 new valves, seals, and gaskets if it isn't going to fix it. I'm in Princeton, IN by the way.

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I have an 07 and it smokes when its cold but only when i rev it and only a little puff of smoke comes out other than that it stopes as soon as the bike is warm

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my 08 does the same thing as yours ryan348. I just asume its normal when there cold. What part of B.C. do you live in?

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cool man, I live in Terrace. I was just in PG a couple weeks ago. i plan on coming rding there sometime this summer. maybee i'll give you a shout on here when I make it back up there.

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im pretty sure its not normal for a 4 stroke to be smoking...not trying to stir up trouble, im jsut saying...it could lead to bigger problems if you dont assess it now.

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man well i dont know about this guys bike but myn really doesnt smoke only like a little tiny puff of blue when reved with the choke on... so im pretty sure its fine

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Yah mine is the same. only a little puff when its first started and i give it a blip of throttle. Its usually gone within 30 seconds. plus I only have 15 hours on the bike and all my valves are in spec and its running excelent. Im pretty sure its just residual fuel in the idle circuit that gets burned when you blip the throttle.

By the way I like track and hill climbing, but a trail every now and then doesent hurt.

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yea i ride track right now nothing is open because we still have some snow but im preacticing at a mini track at a local gravel pit

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Yah our track is still a little snowy, but it should be good by next week or so, but besides that pretty much all of the snow is gone now in Terrace.

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