Not really sure what you mean. Pictures would help.

Also, by "stand tubes" do you mean the actual metal tubes that adjust up and down, or the plastic inserts at the top of each section that "grip" the metal tube when you tighten the wing bolt?

How long have you had the stands? It might be time to just simply replace them.

Here is a pic, you can see that the insert is coming out. I have three stands with this issue. Guess I was over-tightening in my younger days.

I prefer not to replace the stands as they are super durable (double bracing) and work well, outside of the stripped wing bolt inserts of course. Maybe I'll try some JB Weld to glue the insert back in.

I've had the same problem with those older stands, not only Yamaha.

Some, I've been able to re-flare and re-seat them. Others are kind of toast. Since yours has the insert, you can try to press it back into the stand and flare the backside of the insert. If you try this, make sure to put a same thread bolt (don't use the winged bolt) so you don't damage the interior threads. With a punch, tap the edges of the back side of the brass back into a flare (do this with the bolt threaded all the way in). Once the back side is flared out and overlapping the soft metal (the chrome part of the stand) punch up the front side.

You can try epoxy or liquid weld, but I'm not sure how long it will hold. The next best thing, if you're really in love with that stand, is to take it to a welder and have them weld or solder the original or a new threaded insert in place.

Best of luck!

Thanks, I'll give that a shot!