2004 YZ450F Big Bore Kit

2 replies to this topic
  • PhoenixBigBore

Posted May 17, 2015 - 08:16 PM


Hello all.  Quick question....Just picked up a retired supercross bike with blown motor, so I ordered a new Cylinder Works big bore piston and cylinder for rebuild.  I also have ordered a new crank for the bottom end from a local shop.  I'm a graduate of MMI and current Polaris Tech, and I have done a few builds before, so I have the tools and ability to complete the rebuild, but looking for any tips (or links to older posts) for this specific model, just in case anyone came across anything strange along the way.  Looking for advice from anyone that has completed the same build, or maybe a tip on jetting, etc.  Thanks!

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  • grayracer513

Posted May 18, 2015 - 06:40 AM


Nothing other than straightforward, really, but a manual is important:






I would advise having the engine balanced for the big bore kit, though. 

  • PhoenixBigBore

Posted May 19, 2015 - 04:37 PM


Awesome! Thanks for the info, too! I'll let you know when I get it running.

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