Cracked Frame On '03 YZ 450F

17 replies to this topic
  • DBJR

Posted July 06, 2004 - 10:15 PM


I just noticed yesterday that my frame is cracked along the lower weld where the stem meets the lower tube. It's cracked along the entire weld and has started to spread through the lower tube. Has anyone heard of this happening before? Any feedback would be greatly appreciated.
P.S. I suggest that anyone who rides motocross with their 450 check this area carefully, because the result of a complete failure in this area would not be pretty! If you see oil leaking from this area check it immediately so you can get it repaired. If not it'll get as bad as mine and you'll have to get a new frame like I do.

  • DPW

Posted July 07, 2004 - 02:55 AM


Have any pictures of the cracked frame?

  • laterskx

Posted July 07, 2004 - 08:06 AM


I read your post today and went checked my bike out. :thumbsup: Good thing you said somthing because i've never noticed it but mine is cracked in the same place. I did some more studying and found that it might be more common than one would think. Word to evry body out there check this out.

  • DBJR

Posted July 07, 2004 - 06:13 PM


Have any pictures of the cracked frame?

Here are a couple of pics.

  • bigc

Posted July 07, 2004 - 10:46 PM


man, those are some really ugly cracks.I will be taking a look at mine!

  • endurodog

Posted July 08, 2004 - 03:22 AM


I followed a guy over a double jump a few years ago. When he landed he just slowed down and stopped in the middle of the track. I couldn't figure out what was wrong. I turned about and went back and his frame had broke in that spot, the front wheel pushed out and the frame was sitting on the ground, didn't break all the way through. He avoided a nasty crash. I can't remember what kind of bike he was ridding.

That crack has some scary possiblities!

  • JYD

Posted July 08, 2004 - 05:17 AM


are you planning on repairing, or replacing that frame?

if you are getting rid of it, id like to take it off yer hands.

  • Ga426owner

Posted July 08, 2004 - 06:50 AM


I suggest some calls to Yamaha are what you all should do. If this is a problem there should be a call log started....I looked at mine and i do not have a crack like that. I do however have the paint chipping at the weld on the bottom of the stem at the weld to the lower frame tube. :thumbsup:

  • Siers55

Posted July 10, 2004 - 03:25 AM


I had my frame crack as well. However it was the weld that broke. My broken weld was at the subframe mount just behind the tank. I recommend you take a look at this one as well. A couple of guys at the track said the had seen several frames cracked at the steering stem on 450's. :thumbsup:

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  • Jeffro426

Posted July 10, 2004 - 06:49 AM


You best bet would to be to take the bike apart, strip the frame, inspect VERY thouroghly for any more signs of stress, then take it it a trusted welder and have him repair it.

  • dirt_pilot

Posted July 12, 2004 - 07:57 PM


I thought I was the only one till I saw this post. If you weld the joint will it be as good as new? Is it time to sell it? Mine is leaking oil but the crack is real small. My friend says it is most likely due to bottoming the forks on harsh landings.

  • stevie

Posted August 09, 2004 - 12:08 AM


I noticed the same type of crack around the head tube on my bike last week. Oil was seeping out and dust was sticking to it that's how I noticed it. Its the weld that was broke but no-where nearly as bad as the ones in the pics.
I cleaned all the paint off and stripped the clamps out of the frame and had it welded. I raced on Saturday with no problems from that area but there is another tiny pinhole on down the frame at a weld. I will fix it too, but hope that this is'nt the way things are going to be from now on!

I think maybe bottoming the forks hard may have something to do with it? Has anyone any updates on how there bikes have been since being welded?

I think also that there are probably many times when bikes have small defects in the welds in frames and the only reason that we (yamaha 4 stroke owners) pick up on it is because our frames carry oil in them, whilst alot of other models don't.

I am seriously pissed off now, as this is coming straight after a major rebuild.

  • tom_dappert

Posted August 15, 2004 - 06:12 AM


I have both Hondas and Yamahas. I have yet to be impressed with Yamahas welding abilities. Generaly, very sloppy compared to Honda in my opinion. Thanks for the info.


Posted August 15, 2004 - 05:52 PM


Mine was cracked too and until I read this post I only knew of one other that was cracked. I had mine welded and have had no problems since. I don't think Yamaha would do anything about it since dirt bikes are sold with no warranty.

  • criss

Posted November 12, 2004 - 07:48 PM


Same problem with my 03 450,came in from riding yesterday nd noticed oil running down the front of the frame below the steering head.Can't see the exact location of the crack,but thanks to the photos have a better idea of where to look. (guess i shouldn't be spending so much time on the freesyle ramp!) -hopefully welding will fix the problem until the aluminium frames come out?????

  • criss

Posted November 16, 2004 - 06:47 AM


Found the crack,same place as the photo,on the weld just below the steering head. Anybody know about welding the frame,i was told be careful how it is done because its chrom-moly???

  • bbeaver

Posted November 16, 2004 - 07:07 PM


It will have to be tig welded, most bike frames that I've welded with Crown 15 rod,
Proceedure would be Clean weld area, preheat to 250deg. to 300deg. welding with DC str. polarity with argon. it should be post weld heat treated after weld.
If your not a welder, take it to one.

  • criss

Posted November 17, 2004 - 07:21 AM


Thanks for the info,now i just have to find a welder here in malaysia that can do it!

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