YZ timing on '00 WR 400, jetting anyone

YZ timing, YZ pipe with vortip, I'm looking to jet 175 main, 48 pilot, OBDVR needle 4th position, 800 feet above sea. How does this sound? Has anyone gone down this route before. (Man I'm glad I don't ride a 125)

That sounds a little rich on the main to me especially with a Vortip. Also, if you run a 48 PJ, replace the pilot air jet with a #100 size just like a YZ. With the #75 stock pilot air jet on the '00 WR the 45 Pilot jet works better IMHO.

So I think you should buy the #100 PAJ at least.

I tried something close to that and it ran great, but not anywhere near as strong and reliable (in terms of plug fouling, bogging) as using an OBEKN or OBEKP needle #4 (try #3 too) with 48PJ, #100PAJ, 168-172 main. I mean it was a big difference over the DVP! I ran this combo for over a year w/o one single fouled plug (ok maybe one). The DVP was smoother, but I wanted the bike to rip as hard as it can :)

The Kouba T-handle is essential to dial in your fuel screw, too. Don't forget about this screw!

Taffy has some other folks trying the EMM/EMN needles and completely diferent settings than this and working well. Check the jetting Q's post.

I'm currently running an FHP #3, 165MJ, 48PJ, Sudco adjustable pilot air screw at 1.5 turns out with the main air jet completely removed! Seems stronger yet but I haven't given it the full acid test and tweaks yet. Damn rain has ruined the spring experimentation!

If you haven't done thee gray wire and BK mod-just do it!



that jetting is now two years old which is an eternity on this board. i think you could try to look a bit deeper into our records by going to search, especially as you've put down what you're going to run and by that most people will take it that you aren't to be swayed!

the best thing you can do is go read the Jetting Qs thread which has been brought to the top today and have a bloody good read!

then if you want, pluck some jetting posts by going through the last 100 days etc.

remember though that virtually any jetting is better than what you're about to try and that that was just recommended IMHO :):D

you can try my jetting +10 MJ for a more open pipe and the needle one clip lower. that'll do ya for a start.

for some people it works straight off, for others it takes a tickle and others, well others never report back, they just ride into the sunset (but we're not to sure whether that's with the bike running OK or not!).


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