Top end differences between 250F / 450F

6 replies to this topic
  • neevothespaniel

Posted May 02, 2007 - 12:30 AM


I am looking at upgrading to a YZ450F. Could someone tell me if the valve train and top end are the same on both the 250F and 450F.

I am aware of the displacement differences, my question relates to maintenance and the replacement of parts (eg piston, rings, valves etc).

Thanks in advance.

  • Pezman04wrx

Posted May 02, 2007 - 02:32 AM


The design is the same set-up for a 250f and 450f, but obviously everything internal (part wise) is totally different ... So any work (valve shimming/top ends) will be done the same way as your 250f ...

  • neevothespaniel

Posted May 02, 2007 - 03:08 AM


I thought that would be the case. Cheers for the info.

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  • KJ790

Posted May 02, 2007 - 07:07 AM


The parts on a 450 will wear out slower than a 250F because of the lower RPMs that it runs most of the time. Other than that, go about it maintaining it the same as a 250F.

  • neevothespaniel

Posted May 02, 2007 - 02:29 PM


So you get more power... a stronger longer lasting motor... simple maintenance like a 250F...

... Why doesn't everyone get the 450F :applause:

  • grayracer513

Posted May 02, 2007 - 03:51 PM


Because they are afraid of them.

  • neevothespaniel

Posted May 03, 2007 - 04:00 AM


Of course I should have know what :applause:

And indeed I will fully understand it when it dumps my ass :applause:

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