this should be yzf anonymous

Ok this problem is beginning to sound a bit redundant to be considering some of these bikes "lemons". Here's a quick summary of my experience, bought 01' fouled a dozen plugs on first tank of gas would sometimes start on fresh plug only to backfire until plugged was completely fouled and would not spark. Had dealer check out first time they blamed me and my riding I ride woods not mxross and this was disproved by an employee of the dealership the second time who rode one and said they can be ridden at any speed and load without fouling. They replaced carb (didn't tell me why) fixed problem somewhat fouled two plugs afterwards once because of petcock on found TT did Blue Wire mod, haven't fouled plug since. I agree with you Mike a $6K bike (mine will be $8K after loan) should not have to be screwed with in order to be ridden normally racing is another thing. Before this bike had been riding a 85' IT 200 rebuilt once 8 years ago changed the clip on the throttle slide once and have never had a problem their are bikes that a built and engineered to last I just think that the 426 is an extreme maching and I can accept little quirks here and there as long as I don't ever have to change a freakin plug in the middle of the woods. Anyone heard or think we will ever here anything from the factory guys (i.e. bad carb castings?) Good luck mike

First of all thanks for the helpful input, I have been riding a long time and I know a descent amount about bikes. I never left the gas on any bike, my filter isn't over oiled, the jetting seems to be crisp as can be. I could be guilty of not rolling the throttle on slow enough (can that really kill my plugs this fast though). I am going to the dealer on tuesday. AND BOIT, HAVE YOU EVER RIDEN ANOTHER BIKE,NAME ONE THAT HAS ANY SYMPTON i HAVE DESCRIBED ABOVE, THEY DON'T ACT LIKE THIS THING i HAVE IN MY GARAGE. i KNOW IT HURTS YOUR FEELINGS WHEN i TALK BAD ABOUT YAMAHA, BUT i AM PISSED, SO STOP TALKING.


I am sure you know this ,but, these carbs have an accelerator pump ,which, shoots more fuel into the intake, thus, may foul your plug when the throttle is chopped. Good luck at the dealer just be nice to him...I have the same problem I have a wicked evil temper too. People are way more helpful when I don't rip their heads off. It has taken years to relize that. I am sure he will be willing to help. He doesn't want to loose a future customer.

[ May 06, 2002: Message edited by: Kermit ]

This is my reply. Alot of manufacturing people read this website, they know what is going on. Do you think anyone of them would jump out of the clouds and give solutions? I don't think so. Maybe we should have bought a Cannondale. They at least listen. There is definately a problem with minimal fixes. If I bought a car/truck that run like this, it would be all over Dateline, and we would get an answer (or a refund). The way Yamaha is handling this, is the same way they bombed Pearl Harbor. I hate to sound like this, but this is they way I feel. Left out to dry!


I feel absolutely no loyalty to Yamaha. I totally agree that you and all other owners should not have to be fighting these problems. It appeared to me that your original post was a thinly disguised attempt to pitt one brand against another. Apparently, I was wrong and I apologize for that. Not much more I can do than that.

I would have to agree OZZY. I like the tinkering, but, for 6 grand we really shouldn't have to mess with it. Of coarse none of this bitching does a damn thing. I would be nice if it were like my Toyota truck just get in and drive...maybe Toyota should start making dirtbikes? would be hella expensive. It would run forever though.

[ May 07, 2002: Message edited by: Kermit ]

Just went out to load up, will not start, 9th plug and all the other suff> truning off gas, jeting four times, blue wire and lets not foget the DRILLLLLLLL*&^%$#@@@! What is up this????? My point is that some at YAMAHA should be better than the next guy. do they realy think that we care how wins the super cross. no not realy so speak up on this you will win you more than you know

alos my kids kx65 firts kick. and i jeted it . :)

My friend and I bought our 426's at the same time, his a 00' and mine a 01', I have fouled $40 worth of spark plugs since and the 01's are supposed to have easier starting. I have since put a K&N air filter (30% more air), run a hotter plug, and adjusted the air screw and now have not fouled a plug since. I have spent many a hour in the middle of the dunes waiting for my friend (on his 00') to bring a new plug out to me, but finally things are "dialed in".

I wanted to ditch the POS many times, but after I finally got things "dialed in", I would not give this bike up for anything.

Hey Mike. Sounds to me like you may have bad fuel.

I'd drain it out and then pour it on the groung and light it. Some times I make little gas rivers

and float little green plastic army men in boats

down em. Fire crackers are good too!

Then I'd get some new fresh gas. I like the good stuff c-12 b-32 some guys say ya dont need it

but You cant beat the jetting consistancy. And it smells good too. You should be able to get a 55 for lessthan $225 Or for $225 you could get 45

plugs. Get the gas. I switched to decaffe a coupl years ago. You should try it.

Respectfully Herbski

Man, my 99 YZ400 runs so damn well that I'm afraid to buy a new yamaha. Good Luck Guys

Hey Dude,

I am with Herbski or Herpies or whatever his name was. Go with the decaf and a little river of fire, sounds to me like you are heading for CNN about now.....Take the piece of crap back to the dealer and go with the old school..I have an AC Corba that beats the **** out of any Viper that comes along and it's 34 years old...


Most here seem to be blaming you for the faults, myself included. I can speak for myself and maybe most, that were sorry for your troubles and glad we don't have to endure the crap your going through. These bikes are assembled by HAND so human error can effect at any time.

We know that were proud of these machines and if you can get yours dialed in you'd be happy as well.

I know I can speak for everyone and say were glad were not in your shoes if you do have a lemon.

Enough said.

Do take your bike back to the dealer, but try one thing.

Wet plugs equal too much air = rich setting.

Check your pilot airscrew at the bottom of the carb. Stock setting is 1 3/8 turn out. Turning in equals lean setting turning out equal’s rich setting. (These are set manually by humans at the factory) It’s worth a try.

Good Luck.

You may have gotten a bunch of "winter" gas that has a problem. Id go buy 2 gallons of race gas and see how that works. I just read another thread that stated he squared away a plug problem with race gas. The problem is probably a bad batch of gas. If it was your car you wouldnt notice, but they run sooooooo lean that it almost doesnt matter when they get a bad batch.

For the post about owning a Toyota; if you want a bike that fires up every time and never breaks, go buy an XR400. Like the toyota it's reliable, boring, and slow.

Go talk to a bunch of guys who own Porche 911's, Lamborghini Diablos, or Ferrari F-50's. I bet you would find a few that have had problems with their machines they couldn't fix themselves for free. They probably spent a lot of time at the dealership and plunked down some serious coin to get the issue resolved.

I think the problem is that you're not being realistic. First off, you have no stats about the model or year of your motorcycle that indicates how frequently this problem occurs, yet you bash Yamaha for making bad motorcycles in general. I saw quite a few posts here that indicated that they've never fouled a plug regardless of what they've done to the bike (like myself).

Next, you expect that your highly sensitive racing bike run perfectly out of the box. As a lot of folks have indicated here, once you find the fix, the problem goes away. These bikes run awesome when they're dialed in and pretty poor when they're not. I heard you mention a lot about fouled plugs, but not much about structured problem solving to investigate what is causing the fouling. Perhaps instead of riding it and continuing to foul plugs, you should brainstorm all possible reasons a plug could foul (perhaps with your dealers assistance?) and systematically eliminate possible causes until you uncover the root cause. If you're not inclined to do this yourself, I agree the dealership should do this for you since your bike did it since you bought it.

Also, you're kinda preaching to the choir here. Everyone (or most everyone) on this board came here to learn about their bike and perhaps how to make it better. Most came because they have an issue they think a fellow TT'er knows the fix for. So perhaps instead of initiating a message by bashing Yamaha for making a POS bike, you could fully explain your problem and solicit feedback on possible fixes? Seems all you've done is alienate some really experienced folks from helping you out.

I am truly sorry your bike isn't running as well as other bikes here. I really enjoy my 426 every time I take it out (except the one time I put the cam back in it with incorrect timing...DOH!). Unfortunately I'm not an expert on plug fouling and don't have much to offer to you. I would suggest if you don't have the money/time/willpower to troubleshoot it yourself, take it back to the dealer and demand they fix it or exchange it.

As for all of you that wrote in complaining about how Yamaha won't pony up to their mistakes like automakers, keep in mind that automakers sell millions of cars every year and make billions of dollars doing so. Because of that, some very powerful consumer advocacy (sp?) groups have formed that make life hell for auto makers if they screw up. Ford/Chevy/Dodge/Toyota won't willing admit to failure and offer new parts and free labor to fix something unless they're pressured to do so. I think Yamaha gets away with this not because they're any different than the big automakers, but because we as consumers allow it to happen.

Sorry for the long post, work is boring today...

[ May 07, 2002: Message edited by: bbeakley ]

P.S. If you're still really upset at Yamaha when this is all over and done with, go buy the Hokoda you referred to or the CRF or the pumpkin. You'll lose your ass selling a used YZ426 and have new and different problems on any of those bikes. (never heard of a Hokoda, your brand new $6300 CRF will need a new airboot and a $500 triple clamp so it doesn't wobble at top speed, and the pumpkin has marginal suspension, unless you're used to European bikes...not my personal opinions, just regurgitating what I've heard). But at least then you'd be crying to a different discussion board about your problems.


I have owned numerous bikes and never wined about any of them. And if I did buy a Honda, KTM, or any other two stroke 250 I know what needs to be done to work the querks out of them. Right now I have to pay some guy 60 Bucks an hour to figure out what the hell is wrong with my new bike(right now it's sitting at ACtion Motorsports) Sereously, you can't tell me that I have unreasonable expectations.

And another thing, I have always wanted to own a 426, I Had nothing against Yamaha, I have something against a company who charges me 6 grand for a god dam rubix cube.

And Boit, I understand.

P.S. Beakley, if you can't sleep tonight, just jump on T.T. and tell me I am right. It'll help.

Why do you have to pay $60 per hour. Isn't it still under warranty?

my dad owns a 426. he sometimes has a very difficult time starting the bike. on cold, or moist days, it seems she will never fire!!!! I just walk over to my 520, give it one half hearted kick, no choke, and it FIRES to life. He always just looks at me and curses Yamaha.

The point I believe Mike is trying to make, and I can agree, that when Honda and KTM make a bike that starts like it's got an e-button, even when it doesn't, why can't Yamaha do the same thing. It's stupid.

That aside....Mike, how tall are you? ONe thing my dad DID do that has significantly helped his starting abilities, is build a box to start it on. He is 5'6", and has a tough time starting it on level ground. he must be a good 6-8 inches higher to get it to start. I am 6'0", and yeah, I have had tough times starting his bike too. I would think it is indeed all jetting though. He is still running stock.

The thing is, the bike doesn't even sound like it is TRYING to start. Something else we do to get his to fire:

-turn the fuel off.

-Tip the bike over until the carb drains.

-Hold the throttle WIDE OPEN. Hold in the compression release.

-With the throttle wide open, kick the bugger 8-10 times, just like a 2 stroke, just plow through.

-Let go of the comp. release and throttle.

-Turn the fuel back on, and do your normal routine. This should help.

You are not alone in your starting harrassment, but there is a simple fix to help but not entirely cure hard starts, and it does not involve blue wires, grey wires, or anything else, it probably involves jets.

Needless to say though, my dad and I can understand your frustration, as like I said, I can walk over to my stock ktm, on an old plug, and 1 kick she'll fire, yet dad can fight for 20 mintues sometimes to get his to. That is indeed frustrating.

bBeakly....yeah I know My Toyota is boring and slow. can't really haul a bike in a Ferrari I have big plans for her...600 hp prerunner. Of coarse I am going to yank out that trusty 4 banger. Put a full cage front to back try to get 20+ inches of travel. I don't think your Ferrari can touch it in the dirt. My friend has a XR400 I rather have a cranky Yz than that thing.

My bike had the same problems new . I went and bought 5 extra plugs . I had the popping on decel. I found out why mine stalled so easy. the idle was set way to low . So I would blip the throttle fast and it would stall . I also did the blue wire mod. It started perfect ever since - have yet to install a new plug since. I feel your pain . I was about to get rid of my $5500 boat anchor at first to . I bet I fouled 10 plugs up to the point of the blue wire mod and setting my idle right. I used to worry if I got to far away from the truck I would be walking back to it . I now have new found love for the bike and never regret buying it. I never even think about it not starting anymore or stalling . Also I have yet to use the hot start button since the blue wire was unhooked . Keep us posted on what the dealer finds out . In my opinion Its just trial and error until it all comes together . my bike stalled ( It was the idle ) My bike wouldnt start ( the blue wire mod ) . Now its all good . I love the 426 and it finally is worth the money. ( just my $.02 ) Take care and I hope you get to love your bike also. Ryan

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now