Warning: 02 YZ250/125 airbox problem

[MX-727]

Today at the shop, the guys showed me several YZ's that all had the same problem with the airbox. Basically, a flaw in the design will allow dirt to get by the flange in the airbox. One of the engines was trashed.

The black plastic piece that is bolted to the inside of the airbox is slightly warped at the 3 and 9 o'clock postions. This is where the cross piece that holds the nut for the bolt that holds the filter is molded. Suggest everyone check this piece and silcon between it and the airbox if you haven't already done it. All three of the pieces I saw today had tracks of dirt on the plastic at these points. The bike that seized had quite a bit of dirt in the mouth of the carb. I'll see if I can get some pictures.

 

[NO HAND]

Originally posted by KX - 727
Today at the shop, the guys showed me several YZ's that all had the same problem with the airbox. Basically, a flaw in the design will allow dirt to get by the flange in the airbox. One of the engines was trashed.

Hum, that would be a real fit and finish problem:p Just kidding, I had to throw that one back to Coop. ;) I know Hondas are the same...if not worse, they are just not alone anymore:eek:

 

[podia]

A picture will explain a thousand words.:D

 

[MXP1MP]

Really? I haven't noticed this at all with my bike compared to my '01 CR the air box all together seals up much better. Everytime I've cleaned the air fliter on the bike now no dirt has made it into the boot at all.

 

[Coop37]

We have sold 20-30 125's&250's, and havent seen anything like that ? the only thing I can see happening is the clamp inside the air boxmay be getting over torqued, and deforming? let see some pic's of what is happening, more than likely it is human error. ( not enough filter oil, loose air filter, or just plan wasnt cleaned enough), I will double check with yamaha, and get back with ya.
And if there is a defect, or fit and finish problem(like the honda's, that have the best fit and finish) you can bet yamaha will stand behind it 100%!!!!

 

[hoosierf]

Coop:

I have to take exception to "Yamaha will stand behind it 100%." I'll couch what I'm about to say by telling you that I have an '02 YZ250, so they didn't scare me completely away and I think their product is the best performer out there. Here comes the but. I had a crank failure on my YZ250F and Yamaha screwed me like a two dollar whore.

Their stuff better remain good because their cust service sucks!

 

[Coop37]

hoosierf, That really has nothing to do with yamaha, and eveything to do with your dealership that represented you to yamaha rta, I have never had any problems with my rta, I have Had 1 crank go bad on a wr250f, and the machine was 1 year out of wty, and they paided for all parts !!!, even knowing that the customer was running a differnent oil!!
The 100% I am talking about is the honda owner that call honda rta about the air box and had a hell of a time. ( That wouldnt happen in this case, if they know they have a defect, they will fix it, period

 

[hoosierf]

Coop:

That being the case, I'm glad I changed dealers for the '02 YZ!

 

[Coop37]

hoosierf, if you have any problems, give me a call !

 

[marcusgunby]

Coop your bias is just a step too far-ive known Yamahas to have plenty of problems that they have not backed as i have KTMs and Hondas.You make it sound like Yamaha is your best friend that will take you out for lunch every week.Most manufacturers when they replace stuff is only because they are bothered about bad PR not becuase they actually care-its all big corporate business.If Yamaha are soo good why did it take them 4 years to recall the throttle pulley wheel-im not trying to say Honda/KTM etc are better but lets be honest.

 

[Coop37]

marcusgunby, As for the throtle pulley recall, I have never seen the problem?(I have owned a new yz every year sense 1989)
but yet they are recalling them anyway, that just tells me they stand behind there product.(I have been dealing with yamaha, suzuki, polaris for 20 years)
And yes, Me and all the rta's at yamaha are real good friends, and that helps alot, for both of us. And if I didnt live 14hrs away from them we would be eating lunch.(I did go to disenyland with the The top brass at yamaha rta.)
As for being loyal to yamaha, yes I am, and I blame that on the great guys at yamaha!
As for KTM, I dont know yet about them, as we just became a KTM dealer.

quote: Most manufacturers when they replace stuff is only because they are bothered about bad PR not becuase they actually care-its all big corporate business

Well thats how they know of a problem, is from us,and that is why they want to take care of the problem, you know the old saying, "one bad mouth spreads 10 times that of a good mouth."

They dont want bad "PR" they want happy mouths
:D

 

[motometal]

what does "rta" stand for?

 

[Coop37]

Regional technical assistance:confused:

 

[MX-727]

I still don't have the pics, but the leak isn't associated with the filter. It is between the black plastic mount inside the airbox and the airbox itself. Take the filter off and the black plastic ring that is attached to the airbox is the culprit. The leak isn't readily detected until you remove the ring and look at the outside edge of the flange that actually slides through the airbox.

Pictures tomorrow.

A lot of folks routinely silcone around the airbox, anyone that does won't have this problem.

 

[marcusgunby]

coop maybe you should talk to the riders who throttle stuck wide open and got injured- probably to be told it was there bad mechanicing skills ,at least that would have been the line for the last 4 years but then all off a sudden there is a recall -i wonder how many riders were injured if this problem has existed for 4 years-no doubt Yamaha only found out recently. They would not try to bury the problem nooo not Yamaha, got morals they have.Just took them 4 years to really get to the bottom of the problem-complicated thing a throttle assembly.While you are speaking to the big wigs i could do with a new free bike-one where the throttle doesnt stick if you dont mind.
Do you remember the 96 YZ125- if you landed hard from a sx type jump with the throttle on it would brake the gearbox-not a nice thing-yes yamaha did replace the parts but it isnt exactly safe is it.:mad:

 

[MX-727]

Here are the pictures. First one if of the airbox with the ring still in place. To take it out, loosen the clamp and pull the ring out.

 

[MX-727]

This picture is of the removed ring, viewed from the carb side. The ninety degree flange which projects towards the viewer is normally inserted into the clamp that was mentioned in the previous picture. You can see a slight bow in this flange at the 3 o'clock postion corresponding to the point where the cross brace for the airfilter holding nut is molded. This is the point that the leaks have occured with visible dirt tracked along the vertical surface.

 

[Coop37]

marcusgunby, I have tryed to find someone that has had this problem, I have only ran about 300 wty's. on the throtle pulley, and guess what ? no one in my area has had it happen ? The problem supposedly happens when there is too much throtle free play, and the cable jumps out of the pulley, and sticks? So if the problem is throtle free play slack, what does that tell ya? can you say lack of cable adjustment intervals, And we all know what happens to cable that has too much free play now dont we, they kink the cable, then the cable frays, and then what can happen? can we say throtle stick!!

KX 727, I will check into it tomorrow,

 

[JTT]

Originally posted by Coop37
I have Had 1 crank go bad on a wr250f, and the machine was 1 year out of wty, and they paided for all parts !!!, even knowing that the customer was running a differnent oil!!

...I have seen Honda replace cams on V4 street bikes from the 80's that were 5 years over warranty, so what? You are right in that it makes all the difference, who the dealer is submitting the claim, and how far the manufacturer in question will go to keep THEM happy. I applaud your loyalty, but keep it realistic.

 

[Coop37]

JTT, tell me what I have said that is un- realistic?

 

[Coop37]

Just got off the phone with yamaha rta, they said they have had a couple bikes that took in dirt, due to over tightening the clamp in the air box, and deforming the cage, but no defect.
When you guys take that cage out, for any reason, dont over tighten it.!
and maybe do like kx 727 said, put some silicone in the sealing area, let it dry and then lightly tighten clamp. I have had mine sense july and never pulled the cage out, ( I have a acerbis air filter cover,and wash mine out every ride)
and I have never sucked dirt, same with all the guy that I ride with, with 2002 yz's,

 

[bwalker]

Silicone dissolves when exposed to gasoline so it wouldnt work too great in this application. Weather strip adhesive is gasoline resistant and works much better

 

[marcusgunby]

Now theres a suprise its the riders/bike builders fault now for overtightening the screws-i wonder if thats what they said about the throttle assemblies for the last 4 years-maybe the flange is under engineered for the job it has and its a fit and finish problem--Coop i work in the kidney machine repair industry in the Uk and nearly all the manufactures come out with exactly the kind of std answers im hearing here but only a couple of months later we get a recall and free modified parts-im bored and ive had enough of this topic-Yamaha make good bikes, but mostly no better than the others.

 

[steve125]

Thanks Coop for the heads up on this,i just checked my air box seal and it's ok. The most important advice in this thread is Ben's comment on not using silicone seal anywhere gas fumes are present! The last thing you need is to have that stuff come loose and clog your carby just before a big double:scream:

 

[Coop37]

O.K marcusgunby your right !!! :scream:
Anyway all you 02 yz owners, if you pull your air filter cage out, dont over tighten, and as for now, I havent seen the problem. enough said.