Loss of low end W/YZ timing?

I'm YZ timing my '00 WR this weekend but I'm a little concerned with loss of low end if any. Thanks!


2000 WR400 stock,(not for long), 2001 TT-R125L (son), 2001 breeze (son, wife)

Yes.. you will loose some low end. The Wr's Exhaust valves open later than the YZs to produce a bit more backpressure. You will notice a small difference in bottom end. Be glad the WR has a heavier flywheel. Thats the only other difference. It will cause your top end pull to be stronger..at the expense of some bottom end. IF you do alot of trail riding, Id leave it. If you do MX tracks, and Fast rides.. Go for it. :)

I, along w/ several others, have geared the bike down for woods/Moab riding.

I went one smaller on the countershaft, while others have gone two more teeth on the rear.

I am VERY happy w/ the gearing change. It is "Wicked" tight out here in the east :).


'99 WZ with all YZ mods, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, forked over by Pro-Action, OEM YZ tank and IMS seat.


i changed my wr to yz timing the day before an enduro, the bike was more powerful from low revs up, it was far, far better. i detected no loss in bottom end power whatsoever, the top end is so good you'll have to respect the throttle.

as soon as i did the yz timing i started to challenge at the front. the only time i'd swop it is turning right in wet grass when nailing it with the yz timing would see me on my behind.

if i were you i would do it & then see how you get on. a very good rider will love it & be ok. an average rider will stall it a bit more etc & fit a flywheel weight. if you find the increase in performance too much you can always go back.


Taffy, Not to beat a dead horse, but I would like to change the timing on my 01 WR426, I feel that I could definatly handle more explosive power, what would you suggest I do regarding jetting if I change the timing to yz specs? Would it change from the stock jetting? I run a Pro-Curcuit T4. I have read all the old posts and I couldnt weed through all the drilling and needles, could you just give me some simple advice on what to do? Thanks in advance.. Dan

Thanks for your replies, I think I'm going to try the mod; I can always go back.


2000 WR400 stock,(not for long), 2001 TT-R125L (son), 2001 breeze (son, wife)

NH Kevin,

When you went to a 13t countershaft were you able to adjust the chain in w/o removing a link? I purchased a 13t in expectation of having to change gearing for the tight trails in my area. Do you guys think there is really enough difference between a 13/50 and a 14/52 setup. My stock rear sprocket is in nice shape so I opted to replace the worn and cheaper front. The ratio for a 13/50 is 3.85:1 and for a 14/52 3.71:1. I didn't think that the .14 difference was worth spending alot more for a new rear sprocket.



'00 WR 400




i changed the timing & jumped on. da-daaa!!!

ran beautifully first time. so if you are happy with your jetting with the pipe go for it.


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