YZ426 Premature Transmission Problem

To all, I recently bought my brand new 2001 YZ426 and I have been regularly been track practicing while religously changing the oil. Then after just two months of ownership my third gear started popping out, then the same day I noticed strange noises coming from the motor. I thought the 3rd gear problem was me shifting lightly until I heard the weird motor noises. I have heard rumors of third gear problems, but have been unable to get anyone at Yamaha to fess up. Has anyone experienced this and what did it cost you? Thanks for any help anyone can give.

Someone please jump in and correct me if I'm wrong, but I read the messages here almost every day and I have not seen a lot of people with gearbox trouble on the '01 that weren't explained. Therefore I don't think it's a typical failure for this bike. Have you figured out what the bad parts are yet? Maybe knowing that would help you determine the cause.

Finding the cause is what I intend to do, but I find it hard to believe in all my racing years that a bike that is as new, as well maintained and cared for as much as this one would have such a major problem. But, as you stated if this is an isolated incident than it is just a part of life. Unfortunately, some large racing teams, who asked to remain anonimous, have admitted experiencing such 3rd gear troubles. Also, I have yet to bring it in because of service department back log, but I was hoping to walk into Yamaha with a little backing that this maybe more than just bad luck. Well see. Any other thoughts out there? Pricing ideas of what a trans job should cost. I realize it is a very open question. Thanks again.

It wasn't my trans, but when Yamaha hinted that the clutch basket was potentially defective and that they would replace it free if it was cracked or broken, I played a little hardball and got the new basket. If you do get some "evidence" maybe hardball is in order for you as well.

Good Luck!

Try speaking with someone at Montclair Yamaha. I'll bet they have more experience with YZ-4.. failures than anyone elso you can find. While most on this board said I did bad maintenance, or should find a better mechanic, Montclair said "Yeah they do that" in regards to the catastrophic failures I described to them on my bike. They were also most helpful in getting me replacement parts at a good price (out of warranty).

In the last couple of years it has become obvious that the FASTEST desert racers here in the west can not finish races if on a YZ-4.. That is unless they are on a yz that is regularly rebuilt during the season. This may not hold true for MX bikes, but the desert seems to eat YZ's alive.

A friend of mine had a 01 426 blow 3rd gear, replaced and blew again, sold and replaced with a XR-650, soon to be sold. The same guy raced a 2000 or 2001 426 in the Nevada 2000. The bile already had 1 desert season on it, made the entire 2000 no problem, and someone has raced it this year without a problem. Maybe it is just the luck of the draw.

Good luck, and sorry to all who will take exception to my comments, but it is all about opinions here.


Pretend it's flat and give it the gas.

[This message has been edited by YZ400Court (edited September 14, 2001).]

Finally, someone who speaks the truth of a possible trans problem. I have heard countless tails of 3rd gear trouble but no one wants to fess up. Yesterday, I spoke to another mx race team and they too agreed of a problem with 3rd gear. I think as you said it comes down to keeping a maintenance schedule that resembles that of expensive foriegn car and just plain luck.

I have yet to bring the bike into Yamaha, but I am reluctant to do so for fear they won't cover it and then I will be stuck paying the high dealer prices. But it is probably the best bet.

In any case, just 2 1/2 mos. of riding and good amount of care was not enough to help avoid this problem. I am still a proud Yamaha man, but we'll see when I get the bill. Thanks for your advise and insight into the issue.

Isn't the warranty 90 days?

Just called Yamaha, its 30 days. Thanks for the idea to check again.

Blueman, my friend has a 2001 yz 426 that has been ridden only about 7 times. Once by him and 6 by me. The bike came out of gear on me twice. I asked a friend about it and he said to tell your friend to sell the bike. I also told the dealer and he said it was out of warranty. Apparently these bikes do have some problems. Good luck bud.

Originally posted by Blueman:

Just called Yamaha, its 30 days. Thanks for the idea to check again.

Trans problems are not isolated, but rather frequently random.

This is due to the wide dimensional tolerance allowance Yamaha permitted for the gears/shafts,shift forks, and related componentry. Even if all parts were "fitted" to nominal design dimensions, there would still be failurs - primarily because the FEA (Finite Element Analysis) work done by Yamaha Design Engineer did not allow enough cushion (robustness) to prevent failure. This is why on some other brands or model years of bikes you have owned you could abuse the engine without fear of failure.

The same design practices can be applied to the hubs, carb, and clutch on this bike. Resultant, what was marketed and sold to the public as a race bike is such, only at the reliability and durability level of a trail bike.

Once you have the bike out the door 30 days is all you have to return to the dealer. It's always been 30 days, since the early 80's no less, no more.

Good luck to all.


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