00 WR-400 lower end bearing failure

4 replies to this topic
  • mud

Posted February 21, 2005 - 06:57 AM


WR Guru's,
I have a dual sport kit on my WR. 5 Rides after changing the oil "apx. 200 miles" I was flying down the road and the thing locked up like a ford rear end (fun when you are doing 65 on a wet highway). The oil was at the add line but not below. Pulled the oil and had metal fragments in the filter. Pulled it apart and have found the lower end (Crank bearing seized). Seeking advice on recommended crank, rod, bearing etc. Also any advice on other things to check and advice on avoiding this again in the future (other than the obvious of keeping the oil full), run the oil level a little high?, put on a oil cooler?.

For those of you dual sporting your WR's be advised that you are blowing out a lot of oil running at highway speeds, so learn from my mistake and hawk your oil level.


  • bigdrtrdr

Posted February 21, 2005 - 09:03 AM


That sucks,
We shelled a WR400 yesterday on an offroad ride. The wrist pin sepparated from the piston at about redline. Jammed the piston up into the bore through the cylinder wall. Bent the rod and sucked the pit down into the cases.
This is giong to be one spendy re-build.

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  • ss396

Posted July 22, 2010 - 07:40 PM


know what your going through
have a 2000 wr 400 supermotard left intake valve stuck open piston smacked it sheared off valve, demolished cylinder head and cramed valve half way through top of piston. Tire locked up in middle of turn 70mph wasn,t much fun. Rebuilt bike. Rod felt good spun freely another 600miles crank rod needle bearing failure. now in the process of finding new bottom end or getting a crank off ebay bike has been well taken care of oil changed every 375 miles on the dotand valves checked every 1000. just was it's time i guess.

  • matt4x4

Posted July 23, 2010 - 05:18 AM


Eric Gorr will rebuild it for you at a very reasonable price - why not go 420cc at the same time?(if your cylinder needs replating).
Or have Him put a 426 rod on the crank and get a 426 cylinder - they have a beefier small end on the rod.

  • wrrider15

Posted July 23, 2010 - 05:22 PM


best way to avoid it happening is to use your bike what it was built for... off road,with very light road duties like getting from one trail to another via a few kms of road...everyone knows wr's dont like big road duties.


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