03 YZ 450 / Oil dripping out

6 replies to this topic
  • Dube2

Posted August 21, 2006 - 03:49 PM


Hey Guys, need some help, went out yesterday Barstow bout 95deg, no biggie. oil would not stop leaking out. couldn't find from where? lower RH side of radiator, crank case, frame directly front of header, all over the place. opened the dip stick hot just after running, seemed to be over filled. if over filled? where does the breather tube go? what happens to the oil if over filled? :thumbsup:

  • 1BLUEsky

Posted August 21, 2006 - 04:20 PM


I have an 03 WR 450 but the motor is basically the same . The large breather tube usually just drops down from the top of the head/valve cover along the front side of the frame and motor. Trail riders who cross larger creeks may route this up along the top of the frame and into the airbox so as not to suck up water if the engine stalls and runs backward.Overfilling will cause oil to come out of here. Oil may also be coming from the small bolt on the upper right hand side of the engine.This bolt taps into an oil gallery and could be loose or missing. Check too behind your shifter and counter sprocket. Good luck.

  • ktmr

Posted August 21, 2006 - 06:43 PM


Check the decompression plug. If there is not a little rubber plug on the top ride side and just an open hole, that is your problem. I blew mine out of my YZF and had the exact same symptoms you are describing.

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  • Squirly246

Posted August 21, 2006 - 10:05 PM


ktmr is right. this is a well know problem. i had the same problem with my 04. it looks like it is leaking all over the bottom of the right radiator right? the spot where there used to be a decompression lever in the head has a plug that has popped out. Get an aftermarket aluminum plug at the TT Store. The aftermarket one is designed to be retained into the head by the stock bolt. :thumbsup:

  • Twistingrips

Posted August 22, 2006 - 08:14 AM


decompression plug is right.
I just bought and replaced mine.
It came out and oil was on my front frame and right radiator.
Replaced the stock plastic one with a aftermarket plug.
Works great better than stock, no more coming back out
With the screw that holds it in.

  • x2stroker

Posted August 22, 2006 - 09:01 AM


Definitely the decompression Plug. They should have recalled that back in 03.

  • Dube2

Posted August 22, 2006 - 09:23 PM


You guys are awesome, I remember seeing that blank hole w/ the set screw.

Now I know what to do.

Thanks All, :ride: :applause: :thumbsup:

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