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.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 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:

Related Content


YZ450F 03 Sparks driving me crazy by SirAttard

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  57 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.