Yamaha frame question

2 quick thoughts, I’ve been welding a long time. 
 

that would absolutely give me a cause for concern but you also don’t know how the parts were fit up. Either way, you’re looking at a portion of the weld that was a little colder than it needed to be (don’t ask why). 
 

at 7 hours I’d be looping the dealer in just for clarity. The amount of CYA that goes down as soon as Yamaha gets involved is insane, I speak from experience. Document everything.

Pretty sure Yamaha employs monkeys from Izu Shaboten Zoo just down the street from them to weld their frames.

Cover it up with solder and call it good. Nothing to see here 

I'm with the Sand Enjoyer here.

I'd be pissed if mine ended up like that, but it may be right where it counts. (BTW, I'm pissed a lot. )

No easy way of knowing what is really happening. Maybe grind on the ugly spot a bit, and see if it's welded properly under it.

I can't tell where it is, so that obviously matters.

Another thing, in case someone says “weld over it again”… don’t. It would be very easy to clean and do a hot pass over that but then you just assumed all liability for that and Yamaha will hang up on you when they find that out. I speak from experience. 
 

your bike your life, I’m not sure I’d ride that though. 

One thing I never see brought up is that when you weld aluminum it messes with the temper a fair bit... I might assume that the frames are annealed to straighten everything then brought up to a T6 condition? (not a welder, but run a company that does deal with aluminum weldments from time to time)

I wonder what it would cost to get some non destructive testing performed on the weld. If it was my bike I would still ride it.

great idea above. Do you have any friends that work for plants that might have an in with someone who can x-ray check? Idk if you can perform that on aluminum or if itll even work but thats a path you can take. 

I have no idea why this is getting downvoted, you're 100% correct.

I've welded Aluminium ( and all sorts of other metals) for Over 5 decades now.

Take the bloody bike to a Yamaha Dealer. 

Be polite, and, arm yourself with as many pictures of Yamaha Frame Failures as you can. Tell them you Don't want to have such a failure. Tell them that you insist the problem be brought to the attention of Yamaha. As I said, be polite - it's Not their fault, it's Yamahas fault.

Even if that is a second pass weld, and those (what looks to be) non fusion / penetration sections shown in your picture (and, you wrote there are similar sections on the other side, but lower down the downtube(?) ) are over a more reasonable 1st pass weld, it's still an incomplete weld.

And, children, it  is F**king Dangerous.

This , for me, is the first picture giving 'cause', leading to the 'effect', that I've  seen over the last few years of Yamaha frame failures.

Yamahas quality control,  inspection, and, indeed their welding robots setting / weld pathways, are not up to standard, with some of their frames, at the least. 

There are Aluminium Alloys that Are Not Heat Treatable.

Weldable ones that need no post weldment heat treatment. 

And that's what the vast majority of Aluminium Motorcycle frames are made of.

Mind you, they can have quite the mix of Alloys, all on the same frame. Ones that should be Heat Treated if they were used in crucial areas, but, not used in those areas. Penny Pinching is applied wherever it can be applied. Sometimes, the Penny Pinching goes a bit too far........ 

 Same bike took this photo after I saw that one broken in half, not entirely sure what to make of it, other welds look good aside from this one seems to be same spot as yours

More than any other manufacturer in history, it looks as if Yamaha chose the least clean environment out of all to do Aluminum welding.

Interesting, I'm definitely not an expert in this area but as far as I knew you could never get past the T4 temper without heat treatment after welding.  Without heat treatment post welding, are there not internal stresses still present regardless of the alloy?

What are we looking at here... a crack or a bad weld?

I would print as many pictures as you could find of Yamaha frames that are broken to show them. They will try to say there is not a problem. 

Just look up Aluminium Alloys.

Predominantly, various 7000 series alloys are put into use on MC Frames.

Most of those, are made to Age Harden  / 'Cure' with No post weld heat treatment.

Using such Alloys, despite their (generally) higher cost than Alloys that Do require post weldment treatment, can present a substantial savings in Not having to do Heat Treatment, Alignment.

Frames using such materials can be back to the required strength just from the time they may spend in storage racks. 

Heck, nearly all Aluminium 'Age Hardens' over time. Artificial Ageing ( in terms of relatively simple 'ovening' can get some alloys up to  T6) Some 6000 series alloys will get back up to T4 / T5+ with (enough ) time between weldment and being put to use.

I refer to 7000 series at the start of this - with the buying power of the major companies, I'm pretty bloody sure they, at times, put to use 'special blend / proprietary ' alloys that we plebs never get near, or will never know the metallurgy of.

I'd dearly love to get a run through on some of the "secret squirrel" materials used by manufacturers . 

I remember when the first GSXRs - and I mean the GSXR400s that came out Before the 750 and 1000s (Rob Phillis's team shoe horned a GS1000 engine into one for the Swan Series here in OZ, before the 750s came out) , I thought, "here we go, fire up the TIG, there's some carnage coming". But, even with those frames being  small dimensional Aluminium, and with an Twin Cradle / Semi  'Seely Type' ( look up Seely frames - one of the first frame makers to 'ty' the swingarm pivot to the headstock , a precursor to Beam type frames - and still made by TGA- and many other makers - , sold by Molnar  and others in the UK / Worldwide ) frame structure, I had very, very few come to me for repairs, other than 'end over ends' suffered on the Track, or road. 

My own Aluminium frames and Swingarms (swingarms mostly) , be they my Bicycle or Motorcycle ones - I've Never had a failure at a weld, nor, near the weld in the HAZE zone. I Do over build them, and, I Do (at times) a few variations of Heat Treatment with them, with Heat Treatable materials being used.  But I've never done full, solution heat treatment on any of them. Goes against the 'rules' ( and I'm Not belittling said rules) at times,  but, as I wrote, over building, good welds, and heat treatment that I can do using old commercial ovens and 'pottery furnaces', has me Not ever having had any  failures. 

With repairs I do, I urge my clients Not to use the repaired item for as long as possible, to as much as a few weeks. But, mostly, I see them being put to use almost immediately..... And, of course, there are often repairs that I Will Not Do. I tell the owner / rider to retire the frame / item to hang on the wall, and, be thankful they didn't have a catastrophic failure. Or, that they Survived a catastrophic failure. 

FWIW, my 2023 YZ450FX weld in the same location looks identical.

I like your response I would add that now that the dealer has been given information and documentation that if you sustain any injury they might be liable in a lawsuit since they were given notice.

You can definitely 3d X-ray aluminum but it has to fit in the X-ray machine and the biggest machine I have seen won’t fit that frame and will cost more than the frame is worth to X-ray. A bigger machine will be even more money. 3d X-ray if used on production parts is usually limited to aircraft and aircraft engine parts.
 

I don’t know if a 2d X-ray of aluminum would give a good enough picture to be useful but even then it won’t take very many shots to exceed the value of the frame. 

2021 YZ450F with about 70 hours

Now that's a problem..

LOF all day brother.

Drill a 1/8 inch hole at both ends and have someone Tig weld it.

Steel is real!!!!