YZ426 450 cross

2 replies to this topic
  • Vinniewho

Posted May 17, 2009 - 12:44 PM


Just picked up a 2001 YZ426 with a "modified S" shaped rod, wasted cylinder and piston minus wrist pin matching "set". Given that the 450 is the same bore but 2+mm longer stroke, I'm wondering if I can mix the 450 cylinder and exhaust cam on the 426 head/cases. I'm guessing it would be a likely fit with a 450 rod but are the 426/450 head/case a decent match, ie; water jackets, oil returns, etc. Has anyone tried this before?
I've always been a 2-smoke fan and this is dirt 4-stroke #1.
Vince in Nor Cal

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted May 17, 2009 - 02:26 PM


There is some evidence that the 450 cylinder will fit, but the 426 head will NOT fit on top of a 450 barrel. Both the head and jug must be changed if they can be used at all.

The 450 exhaust cam can be used in the 426 head, but now that there are aftermarket auto decompression cams for the 426, it's not as important a swap anymore.

  • Kyledvor61

Posted May 17, 2009 - 05:25 PM


what gray said. I have a 426 bottom end and have a 450 cylinder and head on it.

Related Content



Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

Is it worth it? (Cam and High compression piston) by macgi77

Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 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.