2003 yz450f subframe help!

9 replies to this topic
  • boyonblue52

Posted March 02, 2006 - 11:06 AM


I posted before that my tire was rubbing up against my exhuast and i discovered that my subframe had been tweaked in. My problem now is that i dont know where its bent because the seat usualy slips right in those two slot on the top of the frame but there is a 3/32 of and inch space....so i know thast off a bit but also when my rear fender is on it it looks to be off to the left looking from the rear of the bike so i think the whole thing might have shifted i cant tell....also are the lower fender mounts the right side one it like bent upward and the fender shows stress marks around it. i cant figure this out what should i do from here to find out where this frame is bent because i am not in the position to buy a $326 frame....my truck payments and insurance are killer! Please Help

  • bg10459

Posted March 02, 2006 - 11:26 AM


A few ideas.
1. Try measuring between the mounting holes on either side.
2. Put a straight edge on all the surfaces.
3. Thoroughly inspect the welds at the joints for stress or cracks.
4. Sight down each bar to see if they're twisted.
5. Check the mounting holes to see if they might be out of round.
6. Look on eBay for a new one.

  • motohess

Posted March 02, 2006 - 11:27 AM


Not sure about fixing your current sub-frame but if you have to get another keep an eye on EBAY.

  • boyonblue52

Posted March 02, 2006 - 04:03 PM


mmmmkkk i have been but its seems like the whole frame shifted to the left....and how is measureing the gaps ganna help because i have no refrences as of how far off they are...would yamaha be able to give me those specs u think?

  • Ga426owner

Posted March 02, 2006 - 04:18 PM


The subframe on the 2003 is very flexible. I have rebent mine several times. I use either or both a deadweight hammer or a 4-5ft 2x4 or metal pole. I have also straightened one by removing the rear fender and finding either a tree or a post that is stable to use as leverage to bend the subframe back into shape...it is not that hard to fix, unless it is really smashed down. Side to side no problem.. :thumbsup:

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  • bg10459

Posted March 02, 2006 - 05:44 PM


....and how is measureing the gaps ganna help because i have no refrences as of how far off they are

What you're looking for is a difference from one side to the other. Take three measurements on each side; top frame mount to bottom frame mount, top frame mount to seat bolt and bottom frame mount to seat bolt. Compare each side and it may give you an idea of which way to go, maybe not :thumbsup: . Also check that your frame isn't bent; maybe at the lower mounts.

  • kid on a 426

Posted March 02, 2006 - 09:05 PM


if you do buy a new subframe get a wr subframe they are steel while yz's are aluminum and will not bend or flex almost at all

  • bg10459

Posted March 03, 2006 - 08:16 AM


if you do buy a new subframe get a wr subframe they are steel while yz's are aluminum and will not bend or flex almost at all

OK, first, an 03 WR subframe IS aluminum, not sure about older ones. Second, Aluminum is way stiffer than steel. It's the steel that flexes.

  • boyonblue52

Posted March 04, 2006 - 06:16 AM


Ok thanks guys....this is ganna help me a lot....may have some more questions though so pleas stop back.

  • boyonblue52

Posted March 05, 2006 - 10:50 AM


Hey i got it back in place....thanks for all your help i really really appreciate it ALOT.

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