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Trail monkey

2003 Rod broke went through case & Cyl.

17 posts in this topic

First post,

got a 2003 yz450f new, ride hard but never "Raced", we ride at a local track in michigan 7 months outa the year.....well my rod broke last week for no apparent reason, piston not siezed nor is crank, always kept oil clean and well maintained, was not over reved...i was powering up for a jump and it blew taking out the cylinder and the lower case $$$$$

anyone have problem like this or know of a contact at yamaha that might stand behind this motor?

Thanks

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Never heard of that problem. It seems strange to me that if it was well maintained that it would just throw a rod like that? How reved were you for the jump?

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Your post is a bit confusing.

Are you saying that you bought the 2003 new back when it was released or that it is a recently purchased left over model?

Yamaha has a 30 day warranty on their YZ/WR last I checked. Yep, Yamaha warranties even the competition models. I don't know of another manufacturer that does that.

If you purchased it new back in '03 and have ridden it since that time, I would say you are going to be rebuilding a motor on your own dime...and rightly so. It is a race motor....you have ridden it admittedly hard over an extended time...a rod or bearing failed.....these things happen. You may be better off getting another bike $$$ wise.

Hopefully, you aren't expecting a lifetime warranty on a racing machine.

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I would assume it was bought new back in '03. But you know what assuming does :thumbsup::thumbsup:

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I had the same thing happen to my '98 WR400 back in '03. The rod split length-wise about a half inch below the wrist pin and then decided to put itself through the rear part of the case and cylinder. I thought about rebuilding it, but this is my fun hobby and that didn't look too fun, so I found a replacement motor for it and then sold it after my wife talked me into buying a new YZ450. *gotta love her!!*

Might think about finding a used motor to swap it out with, or parting out the bike and buying another. That's the hardship of these fourstrokes, not much in the way of maintenance until they let loose, then it's pretty much a pile of metal wrapped in an excellent chasis.

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I bought it new in 2003, i'm 38, belong to a club and we ride at least once a week....not race, ride. we ride hard yes but this was a fluke in my opinion, i was just powering up under load for the jump and she blew. always took good care of her, very disapointed ,.....pick up new bike friday.....yeeha, and its not BLUE!

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Hi,

How many hours on the bike with same rod ?

You should change it depending on your driving between 100 and 200 hours !

I have a 2005 bike and it has 141 hrs on it already. I changed mine on 115 hrs

Timo Mc

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I bought it new in 2003, i'm 38, belong to a club and we ride at least once a week....not race, ride. we ride hard yes but this was a fluke in my opinion, i was just powering up under load for the jump and she blew. always took good care of her, very disapointed ,.....pick up new bike friday.....yeeha, and its not BLUE!

Are you blaming the brand of bike????

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not expecting a lifetime warrenty, nor blaming the blue bike , but the last thing I thought i'd be doing is scapping my bike because the "Rod" broke for no apparent reason. I wouldn't be supprised if the same rod in my yamaha is the same rod in any other 450, what would you do? i'm thinking its time to try something new.

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Trail monkey,

good to hear, your earlier post insinuated that it was the fault of the manufacturer. Ebay can be a wonderful and cost effective means to get the expensive parts you will need to get the blue beast running again. I have gotten $300 carbs for $40. Don't give up just yet, if you are otherwise pleased with the bike.

Anytime an engine failure occurs, it is a real let down. Sounds like your bike treated you pretty good for nearly 3 years. Did you adjust valves or do any internal work in that time?

I can certainly understand wanting to try something new. Just be aware that Yamaha 's have the most modern 4 stroke experience and are the most reliable bikes around. Imagine loosing a motor in less than a year on the red brand, would you be singing the blue bikes praises then?

I wish you the best of luck with whatever route you choose.

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well my rod broke

anyone have problem like this

I'm rebuilding an '03 450 for an up-and-coming kid. It was given to him as a form of sponsorship. The rod broke, breaking the piston in half at the pin, taking out the balancer, and getting wedged in the crank. It took out both case halves and the cylinder. The engine was full of aluminum shavings, which ruined the oil pump, and the main and balancer bearings. I don't know what started it, but I suspect the piston. What was left of the skirt was completely polished smooth. I'm thinking that the piston was so loose that it finally started disintegrating, making the shavings, locking the oil pump, ruining the engine. Maybe one of those guys from that new TV show "CSI: YZ450F" could figure it out if I sent them the parts. Also, the donating people had the frame powder coated, I wonder if sandblasting media ruined the motor? Anyway, with my donated labor, this 16 yr. old A-class rider is getting a 450 for the $1500 parts price.

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I bought it new in 2003, i'm 38, belong to a club and we ride at least once a week....not race, ride. we ride hard yes but this was a fluke in my opinion, i was just powering up under load for the jump and she blew. always took good care of her, very disapointed ,.....pick up new bike friday.....yeeha, and its not BLUE!

It better be a yz450 se :thumbsup:. I hope its a honda so you know what its really like to have a crappy bike. Were there metal shavings in the oil filter prior to the big boom?

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It sounds to me like you lost oil pressure and that caused it to throw a rod. Who knows what went out first until you pull the motor. I don't think you would have a problem overhauling it with a shop manual and a decent mechanics tool set(including some patience). Don't get to worked up over it, sh*t happens. Did you dump the bike shortly before this jump?

And I would stick with Yamaha if I were you, unless you really want to learn how to rebuild engines. Good luck, and welcome to the club.

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I bought it new in 2003, i'm 38, belong to a club and we ride at least once a week....not race, ride. we ride hard yes but this was a fluke in my opinion, i was just powering up under load for the jump and she blew. always took good care of her, very disapointed ,.....pick up new bike friday.....yeeha, and its not BLUE!

I hope you didn't 100% expect that you could ride it 7 months out of the year for 3 years (estimating, maybe 6-7 hours of riding a month, X 21 months = about 130-150 hours total) with just oil changes and air filter changes...I mean, its may be possible and it happens, I am sure, but you really can't expect it. And don't discount your riding time because you weren't "racing," riding hard practice is just as bad.

Did you ever check the valves or change out the piston? I don't know the rebuild times everyone uses, but I would think about 50 hours or so for a new top end, and check clearances every 10-20 hours on the valves...Yamaha's are known to be the most reliable in those and earlier years, however, that doesn't mean they are invincable, either. In the high-performance four-stroke world, your motor is always a gamble...

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