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ktown yamaha

o6 yz450f blowin white?

19 posts in this topic

hey guys i have a 2006 yz 450f with about 160hrs on it and the other day while i was ridin a trail my buddys noticed it was blowin white smoke really bad not sure wuts goin on, has this happend to anyone ealse bike??

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was it when you hit the throttle? if so thats usually a sign of piston rings going, or if all the time it could be oil seals as well.

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it was just when i hit the gas, but then towards the end of the ride it stoped there was no more smoke wich really bothers me

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White smoke means that water is getting burned in the combustion chamber. It could be a bad head gasket.

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yeah, that sounds like what it could be, at how many hours did you guys chaing your piston rings if you have done them yet?

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if it stopped, could you have gotten water in the pipe when you were washing it? water burning off is white smoke as well.

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usually no more than 50 the piston is changed, depending on how and what you ride, i race mx and ride it pretty hard.

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I change piston and rings every 50 hours. At 160 hours I'd say it wouldn't hurt for you to do it.

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sounds good to me, i think thats wut im going to do fresh piston and rings, head gasket. thanx guys

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You may want to also check the valve seals...just to be sure. I have seen this before with both head gasket & valve seal issues on different bikes

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White STEAM is from coolant, white SMOKE is oil. The difference is that steam will vanish into the air as it cools, whereas smoke won't.

Valve guide seals typically cause a single or very brief puff of smoke on the first cold startup of the day. In advanced cases, they will cause a puff of smoke when you get back on the gas after engine braking.

Smoke under power would be from the rings. However, oil can get by the rings not just because the rings are faulty, but also because the engine is overfilled with oil.

If there is too much oil in the system, the sump can't be completely scavenged, and the crank will throw so much oil up on the cylinder wall that the rings are overwhelmed by it, and smoke will result. This could also explain the fact that it stopped at some point.

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White STEAM is from coolant, white SMOKE is oil. The difference is that steam will vanish into the air as it cools, whereas smoke won't.

Valve guide seals typically cause a single or very brief puff of smoke on the first cold startup of the day. In advanced cases, they will cause a puff of smoke when you get back on the gas after engine braking.

Smoke under power would be from the rings. However, oil can get by the rings not just because the rings are faulty, but also because the engine is overfilled with oil.

If there is too much oil in the system, the sump can't be completely scavenged, and the crank will throw so much oil up on the cylinder wall that the rings are overwhelmed by it, and smoke will result. This could also explain the fact that it stopped at some point.

In all of my experience burning oil (from bad rings or valve seal) always shows up as blue smoke coming out of the exhaust. Maybe certain oils burn white, but I've never seen it.

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In all of mine, I've never understood why people call the color of oil smoke blue. :thumbsup:

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In all of mine, I've never understood why people call the color of oil smoke blue. :thumbsup:

If it is burning oil it tends to come out of the pipe a light blue-gray, then as it fans out you can see it looks a darker blue color. If it is burning water it tends to be a thicker white-gray color and stay that color (or sometimes take on a slight yellow hue) as it fans out.

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Another reason the 'white smoke' may of stopped is because the coolant was consumed. Did you checked the radiator level?

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come to think of it i did do an oil change on my bike and may have put too much oil in it, but who knows, im still going to do the rings regardless. thanks guys for all of your input its much apretiated.

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Another reason the 'white smoke' may of stopped is because the coolant was consumed. Did you checked the radiator level?

:thumbsup: exactly what I was thinking!

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If you can get someone to stand/ride behind it....coolant smells very sweet, but oil has a smokey smell.

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