Uhappy with YZ time?

I YZ timed my 00 WR and I don't think I like it.

I expected it to have a real midrange like the YZ's I've ridden. But I seem to have lost the low end snap I used to have for a bit of a 2 stroke like peakiness.

Yeah there is a little Mid hit but no more top end and the bottom is mellow when it used to explode off the bottom with WR timing. Am I missing something? My wheelie skills just went out the window with YZ timing!

My mods are:

Blueprinted head

Full Ti-4 w' powerbomb

Carbon fibre airbox.

James Now

BK mod

gray wire

162 main, DRQ-4 40 pilot 2 turns out

The one thing I notice is less stalling, I think I am riding the bike higher in the rev range and that is keeping me from blipping the throttle at low revs which I think used to load up the motor with gas causing stalls.

I'm thinking of going with the JD jetting kit.

Do you guys think that will help.

I noted I had to drop the pilot with the James Now.

With the stock 42 the idle dropped as the bike warmed up and I actually foulded a plug for the first time in 3 yrs.

I noticed that it would crack on faster than the WR timing.

It's been 2 years so I don't recall too clearly but I seem to get out of corners faster. I seem to rev a bit higher before letting out the clutch out of (in) the corner to get the rip going.


keep us posted. i was going to be YZ timing my Wr for this years SM race season but every one is telling me to leave it wr timed and that the wr has good enough top end for racing. and that i will love the bottom end even more racing then i do in the bush.

Sounds like something is not right there.

How did you time everything? Are you going by the marks on the chain or actually timing the crank to both cams without looking at the chain marks? the later is correct on how to do this. it is very easy to get some slack in the chain and have it jump the crank gear a few teeth.

Also how is the jetting? Any bog?

What FTD said :) I seemed to able to get out of the corners faster, I like the way it builds revs in the Mid range. I do notice a little loss off the bottom end, and have adjusted my riding style and throttle control accordingly. Just my .02 worth

simon, you probably already know this but........you can't YZ time an '03 or'04 WR. the auto decompression thing gets out of time. you have to swap cams.

Timing the 03 cams different does not make them not work, just a bit harder to start (more leg required or more juice from the batt).

YFZ 450 Cam mod timing change

i would just buy an 04 yz exaust cam.

He doesn't have a 03/04 he's got a 00. I would say something is off somewhere. I just recently (2 months ago) made the switch to yz timing. I didn't notice any loss on bottom. If anything, it wanted to build RPM's quicker. I personally thought that it had more get-up-and-go in every area (low-mid-top).

It should give you piece of mind just knowing that the bike you ride does not have retarded timing. :)

I timed it like the maual says and like I have done in the past, except I retarded the exhaust cam 1 tooth. Now there are 12 pins between the marks rather than 13 as before.

I've got:

"I" mark in the window

Intake came "I" mark right on the head surface.

Exhaust cam "E" mark one tooth up from the head surface, which I believe is YZ timing.

No I did not zip tie the chain to the intake cam and had to put it all back together, but it looks the same as the other 6-8 times I've had the cams out in the past, except the ex cam is turned one tooth clockwise from stock.

Do you think the whole works could be retarded 1 tooth all around?

Would the bike even run then?

Note the ex cam is retarded if the motor turns counter-clockwise and advanced if it runs clockwise.

Dont use the chain marks.

Put the crank at TDC in the timing mark and then line up the cams as such:


I have the stock ex cam, not the auto-decompression cam.

Ya think I did something wrong?

The bike starts and runs fine, I just lost all my low end hit and got back a little peakiness, runs like a 2-smoke now. Gotta use the clutch where I used to just turn the throttle.

sounds suss.. U done the BK mod?

I have YZ timed Wr426 .Any gear, any RPM , crack the throttle and she goes like a cut snake..even from chugging speeds.


You may have done something wrong. I think mine has more mid range and low end than it did before plus it revs quicker as well.

I definetely think that something is wrong. I don't know what, but I noticed more power throughout the range. If you hadn't done the BK Mod before and didn't notice any problems, then that's not it. I didn't have to change jetting either. Just retimed and put back together. I also had an issue with the timing chain slipping off of the crank and I had to retime both cams. When my timing was way off, I couldn't even get the bike to start. When I retimed it everything was fine and it runs perfect now.

I've had the bk mod for some time.

The bike exploded off the bottom before I adjusted the cam timing. It still starts and runs fine just not what I expected. I'm sure the crank "I" mark and the intake "I" mark were all perfect. The ex cam it ot be turned one tooth clockwise right? Not counter-clockwise or anything like that.

I might just change it back and see what happens.

looking from the LH side, then engine runs anticlockwise so to retard the exhaust cam you turn it one tooth clockwise.


I just put the JD jet kit in and the bike woke up quite a bit on the top end. It has a real top end rush now, so I can kinda live w/o the big bottom hit. I think the 162 main I was running was a bit too small. The power is very linear now more mid and top that before.

Thanks everyone.

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