HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
maltisecross

Will a YZ426F head and piston fit on a YZ400F

5 posts in this topic

I love my bike but I am looking to upgrade my motor a bit. I was just wondering if I get a 426 head and piston, would it just bolt on to a 400? Any input on this would be great.:excuseme:

Share this post


Link to post
Share on other sites

you should be good to go. As long as you are doing the complete top end. The bottom end should be virtually the same besides possible gearing differences.

Share this post


Link to post
Share on other sites
you should be good to go. As long as you are doing the complete top end. The bottom end should be virtually the same besides possible gearing differences.
Not so. Review the info at the posted link, and you will see that using the 426 cylinder requires a 426 piston (obviously), and that that in turn requires the use of a 426 rod, because the 426 wrist pin is bigger.

The crank has to be rebuilt with a 426 rod and big end in order for that to work.

Share this post


Link to post
Share on other sites

You also will not see a big performance increase from a head swap. The 400 and 426 heads are virtually identical wiht the exception of the vacuum nipple for the octapus hot start on the 400s. The 426's had the 2nd gen FCR that has hot start internally.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0