My son has a 2009 Yamaha WR450 that the block in the bottom of the swingarm broke off this weekend riding at Anzo-Borrego. Looking at it the welds(heliarc) didn't penatrate the metal, in fact the one on the back side the surface of the swingarm is still smooth. Wondered if any one else had this happen. They don't make a replacement piece as it is considered to be part of the swingarm. I have the old piece, but it is tweeked after going around and bending the sprocket. Not sure I can straighten and get proper alignment for the guide if I get it reattached.
Yamaha WR450 chain guide
Posted December 02, 2013 - 10:53 AM
Just make a replacement out of some Aluminum and get it tig welded on
Not heard of it breaking off before but a big enough impact with a rock / log coupled with a poor weld penetration would result in it becoming detached
Posted December 02, 2013 - 10:56 AM
I have one from my 2006 WR450. It's a bit scrapped, but still straight enough to use. I think they are the same for both years. If you want it just let me know and pay the shipping and I'll send it to you.
Posted December 02, 2013 - 11:04 AM
I think I have broken off 4 in the last 10 years.
I just weld back on a stronger system.
Posted December 05, 2013 - 01:58 AM
Yep that was my bike ... Bastards wouldn't do anything about it . Got new bike through insurance and my new one has been off the the engineer for some weld reinforcement .
unlucky mate. glad insurance covered it.