my 400ex puts out white smoke when ever you let off the throttle hard, does anyone know why it does that. it has a k&n, wb e-series, and has been re-jetted. thanks

 

Your rings are SHOT son!

 

You need to re-ring, but my friends Warrior did the same and he changed his oil and sloved it. If you haven't changed it for a long time you might want to change it twice just to flush it out.

 

we just changed the oil in it yesterday and then it started to do it. if the rings were shot wouldn't smoke when your on the gas not off. it only happens when you let off the gas. i think their is to much gas it the cylinder to burn off.

 

they are right... under acceleration there is pressure in the cylinder to keep the oil out. When you close the throttle it creates vacuum which sucks in some oil past the worn rings. It's either rings or a valve stem seal, do yourself a favor and have the head done to.

 

no if it was burning too rich it would be blowing black smoke out not white. white is a moisture color.

 

well we went riding today and it stoped. it doesn't smoke anymore. i guess thats good. we tried everything to get it to smoke and we couldn't strange.

 

reminds me when I changed the oil in my old lawnmower onetime and over-filled it. Boy did that joker smoke the first couple of times! [img]i/expressions/face-icon-small-wink.gif[/img]