Motor grenades on weekend - HELP!

I was riding my stock 2000 WR400F down a trail last weekend and the motor just locked up. It wouldnt kick over or anything. I took it to the dealer, they took off the top end and it totally grenaded inside! Everything has to be replaced from the cases up! The dealers only explantion is that the chain jumped and everything went out of time, and he isnt even sure if that is it or not! The bike was just fully serviced a couple of weeks ago by the dealer so he should have checked the chain, right? Yamaha tech has seen it and has no idea on what caused the problem, they havent decided on whether it will be warrantied or not. Anyone else hear of anything similar. (I am getting quoted over $2500 US to fix it.)

WOW...maybe bummer. I have my fingers crossed that they will cover it under warranty. I would be VERY professional about the situation and ask they cover it due to the fact that the motor was serviced by the dealer just a few weeks ago and that NO ONE has had this problem on this list despite lot's of screw-ups and mis-use. Don't start yelling at them. Keep your cool. Explain that you are an avid Yamaha buyer, and have great faith in their machinery despite this one freak incident. However also explain that you won't be able to buy another Yamaha if the situation is not resolved in a mutally agreeable fashion.

If none of this works, speak to the regional Yamaha rep about this. Again keep your cool, act professional yet insist the bike be repaired at little or no expense.

If this doesn't work, ask us to help you --there are some folks here that have Yamaha contacts that may be able to help. Also an attorney may help in wording a letter to Yamaha as well if all else fails.

Good luck, keep us posted!

Also.. if you have even had a look under the cam cover yourself and not touvhed anything- DON'T TELL THEM!!

Even though it wouldn't have caused the problem you don't want to leave anything open in which they can blame it on you to avoid a warrantee claim.

Hope it goes well for you! :)



**Ride it like you Stole it!**

Matt Porritt

99 YZ400F

Vist the Rubber Chicken Racing Online Shop

Discounts for ThumperTalk members.

I also had a similar experience, but had a much better outcome. I'm almost embarassed to say, when I was doing all my jetting changes to get the bike set-up with the pipe and silencer I bought. I must have overlooked one of those squeeze clamps on one of the many hoses. I rode the bike around the neighborhood after I got it running and it ran great. I loaded up and headed to the track. When I got there I warmed it up, rode down the road and hit the track. On the first lap, going over the first section of large whoops the bike just stopped. I found TDC and started it. All I could hear was a sound like a rod knock. I immediatly killed the bike and pushed it back to the truck. I was riding with my son and GNCC Jeff. After talking with the dealer I bought it from....who jerked me around I went to the local shop and they let me help take the bike apart (to save cost in case it wasn't warranty work) and when we got the head off I saw the clamp. It must have entered the motor after hitting the first couple of whoops and pinned the valve open and caused it to die. They put it back together for $100 + parts. I was very lucky. I now carry that clamp on my key ring as a reminder to be careful.

The advice you have above is very good.

Good Luck



86TT225, 98CR80, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA.

That is a lot of money. For that price I’ll assume the crank was ruined.

When they say fully serviced that could mean anything.

If I were you I would ask, ever so innocently, if the valves were adjusted. You know, phrase the question to imply that their FAILURE to do so could be at fault (when the opposite is more likely). If they WERE adjusted then that is a pretty strong finger pointing directly at them. There are probably three or four things you could srew up during a valve adjustment that may lead to valves and piston having a chance meeting.

I can’t imagine such a new bike having that kind of engine failure (without the help of some bonehead mechanic). I don’t think anybody here has heard of any engine problems (just clutch and gear problems and other minor glitches). My 426 has some hard hours on it and the entire top end and valve train look new and the cam chain is still stiff and not stretched at all.

At any rate I’m still amazed at the $2,500, even with a new crank. If you get no help on the damage you may want to consider shopping that quote around. But I think a good, levelheaded effort to recoup some of the damage from Yamaha is definitely in order here. I agree with MCarp, I know you are probably really bent (I would be) but try not to lose your temper with them. You may feel better but it won’t help you get your bike running any quicker or cheaper.

Either way that really sucks Jeff. If it is any consolation my bike is probably in just as many pieces as yours (although it isn’t nearly as messed up).

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