2000 vs 2001

what is the real difference between the 2000 426 n the 2001 426. i mean the real difference n not the specifications...


The 1st yr 426 had some mechanical bugs:

1) Blown clutches

2) Jetting woes (hiccup off idle)

3) Rear hubs exploding

4) Something about a keyway shearing off, that was fixed in 01.

The 01 has the Titanium valves that REALLY do allow you to rev the beast and generally are jetted right on for the general masses. I believe the forks were improved also.


Moto to Live

Live to Moto



Its interesting to me that when people ask to compare a newer model to an older model, what is often summarized is the improvements of the newer model. What is often overlooked are the failings, or shortcomings, of the newer model. For example, while the titanium valves on the 2001 model are lighter (allowing for faster revs, ultimately), I have heard of some problems with using titanium for the exhaust, as the temperatures are much higher there than at intake. Rev limiter remains at what?....11,200~11,400 for both the 2000 and 2001. There is no horsepower difference between the two, either...47.5 for both models. I swapped pilots on my 2000, and there is no bog on acceleration...wick the throttle, and you are THERE. Also, you may be aware that with the 2001 model, there has been a major problem with plug fouling due to faulty CDI's. This was not a problem on the 2000 model. Oh, i also believe that the 2001 makes it a bit easier to get to the plug, thanks to a revised header??? (Good thing!!! :) In short, if you are trying to make a choice between the two model years, consider price and maintenance if you are buying both used. I got a real deal on my 2000, and I've been extremely happy with it. My friend has a 2001, and I can't any appreciable differences for myself. Either one should make you happy! Good luck, tuck duck run & gun!

Originally posted by UNCHeelYeah:

My friend has a 2001, and I can't any appreciable differences for myself.


You must not have used the clutch or front brake :)

Actually you make some good points. But the REAL difference between the two in MY garage is:

Either the ’00 clutch is junk or the ’01 is magic, take your pick. I have a Hinson basket in my ’00 and it still doesn’t hold a candle to the ’01.

Same goes for the front brake. I only ride trails and off-road events, no moto whatsoever, and I still am not sure how I put up with the ’00 front brake. I don’t know, but I would imagine this is an even bigger deal if you moto.

The forks don’t seem to bottom quite as harshly. I’ve recently had my ’00 forks serviced, but they are still stock. They are still better than anything else I’ve been on, but I can tell the difference when I hop on my ’01.

Not having to remove the header to get at the oil filter is a plus, too.

Aside from the jetting actually being in the ballpark that is it, as far as I can tell. If you have an ’00 just buy the ’01 needle (the pilot and main are the same). Get the ’01 needle Uncle, it is the best eleven dollar mod I can think of.

One last comment, I have fouled four (4) plugs in my ’01 in about 20 hours. Most were (at least partly) my fault, but this is interesting because I only fouled one in my ’00 in over 100 hours, and it was one size colder than stock, plus I was a YZF neophyte at the time. Not so anymore, I’ve got it jetted correctly, only run NGK 8s and I also reduced the amount of fuel delivered by the accelerator pump considerably. And I’ve still fouled four plugs.

I haven’t experienced any other symptoms to indicate a bad CDI, the thing runs terrific, but it does seem to foul plugs more readily than the ’00.

As for the Ti exhaust valves I think it is a bit premature to label that a shortcoming.

Hope this helps.


HeelllYeah! :) Appreciate the informative response...people like you are the reason I come here to broaden my knowledge. I DO love this forum. I'll check ya out on the 2001 needle! peace!

But the REAL difference between the two in MY garage is:

lol...gotta luvvv that to...lol :)

how do i change the needle on my 2000 426, should i leave it at the same position? never changed a needle before - can u pls help me step by step here?

To clarify, I am talking about changing the needle you have in favor of the part that comes in the ’01, not just changing the clip position.

Either way you have to remove the needle, an easy way to go about this that I’ve seen explained here is to remove the throttle housing from the bars (two screws). I have not tried this because I have bark busters, but I imagine it would be easier than removing the throttle cables from the carb.

Anyway hopefully the throttle can be pulled off the bars by turning them all the way to the right. The object here is to free up enough slack in the cables so you can move the carb and access the slide from the top (this is where the needle is) while leaving the cables attached to the carb.

Once you have the throttle off loosen both clamps that hold the carb on, then you should be able to rotate the carb to the left (or counterclockwise when viewed from back of bike). Then remove the two allen head fasteners that secure the top of the carb. The needle is under a small allen-head cap screw type thing on top of the slide. Remove this and dump the needle out.

Then you can move the clip position or replace the needle.

I don’t have a PN for the std. ’01 needle, I tried Parts Fish but they are showing the wrong #.

5JG-14916-EP-00 is the PN for an optional ’00 needle that is almost identical to the ’01 standard needle, just a half clip leaner (EKP optional ’00 needle vs. EJP stock ’01). This needle in my ’00 almost completely eliminated the “YZ bog” when cracking the throttle, I suppose in my case then it was largely due to being too lean off the bottom, the EKP is 2 sizes (EKP vs. EKR) richer initially, just off the pilot.

I noticed you are not in the US, so you may not have the same jetting. The needle code is clearly stamped on the needle, verify what you have before you change anything.

Hope this helps.

can u help me guys with the part number of the wr426 needle, i want to put it in my yz426 2000. ( here in israel we can get parts only for the wr426, otherwise ill have to order it from usa) thanks for all ur answers - u r the best...

Uh-oh. I don’t know about other bikes, but the jetting the WR comes with here in the US would not work well in the YZ. What you have, if it is the same as a US YZ, is worlds better jetting for that bike than what comes in a US WR.

If you can only get WR parts, how did you come to own the YZ? Was it sold in Israel originally?

At this point I think you should verify what jetting you have now and then post that information along with the avg. temp and elevation you typically ride at.

Hope this helps.

i brought it with me from ny in 4 huge bags.... thats how .here a wr is about 13000 usd !!!!!!!!!! i bought the yz including the taxes that i payed at 8500 usd, so it make me smile when i c the big headline in the new 'dirtbike' 9500$ vertemati like its expensive.....

anyway can u please give me the part number of the 2001 426 that u all recommend....

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