Poor sucker who bought that yz250 conversion I showed a few weeks back. Some guy bought it off ebay and rode it 3 laps the owner did the mod's himself he bought it from. That is one piss poor weld job!

Probabaly used the rod and the MAPP torch they advertise at the fair!

Wow! Can't believe anybody would let that fly! Hope the repair guy is better than the original.

It must still be tricky for even yamaha a 2010 yz450f

Yikes!

Damn some one else just posted another pic of a 2010 yz450 of this same spar weld cracking the upper left side by the head tube.

Dang seeing that 2010 frame tempts me to head out to the shop and dig into mine to ensure that doesn't happen to me. That would be a real bummer deal to a guy that isn't capable of repairing it.

Yeah, that first weld is totally unacceptable, they really need to get some more time on a TIG machine before attempting projects like that...

The Factory weld just shows you that it doesnt take some shmoe in his garage to induce impurities into a weld... Aluminum has to be VERY clean when you weld it, and thats the only thing that makes it tricky, Laying the bead itself is the easy part, it keeping the part clean that will make all the difference in the world.

I realize this is a very old post but be warned, if you're doing this yourself don't use brake cleaner. While unlikely it is possible to create a chemical weapons grade gas. Acetone and a stainless wire brush used on nothing else seems to be the most often recommended methods.

I also recommend 7005 series aluminum which you can precipitation harden in an oven next to your pizza or in a powder coat line.