YZ timing, and I didn't even know!

Well that was a suprise. having stripped to check, I have found out my 2000 WR400 has the exhaust cam clicked around one tooth already.

Now, I am jetting to Taffy format, but I have a question.

What does YZ timing do, and how does the performance compare with stock WR timing?

As a general interest note, what are the main engine differences between a WR and YZ anyway. With my new jets and timing, have I basically got a YZ?

Still looking for a 60 SJ in the UK, if anyone can help.


So, why do they call you TallJohn?

Ok, just kidding!

As for the question, the WR gets its name from the Wide Ratio transmission. Don't know exactly what the gear ratio differences are, but I think that 2nd, 4th, and 5th in the WR are a little taller in the WR than they are in the YZ.

Performing the timing change in my WR created a bike that reached peak rpm's quicker than in stock form. I found this helped me to "lift" the front end (by throttle as opposed to fanning the clutch) when ever an obstacle presents itself along the trail (I also can eat my buddy up, corner to corner, and he has a tricked out 2000 XR650R!). This quicker revving engine was at the expense of maybe 5 or 7 mph off of top end.

I don't know of many reasons to go back.


The wr i think is just a detuned yz with a change to the gearing,i think that is why they run a bit sick!.A bit like if you take a race horse and weight it down,it`s gonna cough an splutter till you set it free!,but unless you want too run it with a straight through pipe and change the gearing it won`t be just like one,but if you let it breath it becomes an awsome machine!.I have an 01-wr426 and yep i`m still trying different carb settings,did the timing when i got it,but a better exhaust let`s them breath!.Try ard-racing they may have the part`s you need.Maybe am just talking nonsense!

Captain S,

ARD came up trumps. The SJ is on it's way. Can't wait to try out my jet powered WR with YZ timing now!


Hope it works for you!,your lucky that you are long in the leg,i tend too keel over from time to time!,lut us know the result,cheers!

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