WR400f to YZ or not?

2 replies to this topic
  • Thommo_400f

Posted January 20, 2013 - 09:05 PM


'99 400f
Going to do a valve clearance check for my first time this weekend.
Seems fairly simple from what I've seen on vids.

So my question is.....
While I have the valve cover off, is it worth trying YZ timing.
I've read a few posts and most like the change but some have said they have had trouble starting after the mod.
I don't want auto-decomp, just rotating the exhaust cam 1 tooth clockwise.

Also I have noticed the top end seems noisy of late, is it possible my cam chain is making the noise or is it more likely to be something else. Most noisy at 1/4 throttle 1st and 2nd gear.
Not sure on how to tell if cam chain is at end of life.

It's been a long haul with this abused beast and I am slowly breathing life into her.

Cheers for all the help so far ;)

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

Posted January 20, 2013 - 10:53 PM


from what i have read you get more grunt when you put on a yzf exhaust,

when i brought my WR426 it had the yz exhaust already and when i changed to yzf timing you feel like you riding a yzf at times but with the stock wr exhaust you may not

good luck buddy

  • Thommo_400f

Posted January 21, 2013 - 12:07 AM


Yeah, I have already opened up airbox and got FMF and Staintune aftermarket very open exhausts.
I guess it's worth a try since its such a relatively simple operation.


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.