2006 yz450 crank bearing?

2 replies to this topic
  • motor_mike923

Posted February 05, 2015 - 09:23 PM


Hello, I recently rebuilt the topend on my 06. I took it out to the randsburg area for some mild trail riding to break it in. It ran great for the first few rides then all of a sudden the motor got tight and cut off. I kicked it a times and the Kickstarter felt very stiff and gritty. After kicking it over a few times it loosened back up and fired up a again for a few minutes before tightening up and stalling out again. Question is, is my bottom end hosed? What is causing it to run tight and stall but then still be able to kick it a few times and it frees up and starts?

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  • xy500

Posted February 06, 2015 - 06:53 AM


Start pulling covers off and see what you can see?
Whatever it is, its likely serious

  • Samcwach

Posted February 06, 2015 - 11:03 AM


Pull the oil filter and look for metal fragments. Drail the oil and swish a magnet around in the drain pan and see if any bearing parts were in the oil. At least it still turns over. You will likely have to pull the crank and check the bearings. I'm sure you'll be able to tell the state of the crank/case bearings by turning the engine over with the cases off. If there's grittiness/hooking up in any of the bearings then you'll have to split the cases and replace the bearings. Also while you have it torn down move the piston/rod to see if there is any hooking up moving the rod back and forth. I'm pretty sure a little play when moving it side to side is ok.

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