Brandon, I'm beginning to think you're not out of luck, maybe you've got enough good steel left in that bearing bore to support a tapered roller kit then just braze up a patch to cover the missing area and act as a steering stop.
It's not really rust, it's grease and grit. The stuff in the hole is the old raceway that I haven't bothered to knock out. I was actually thinking of squaring up the hole and brazing in a piece to fill it and then brazing in another piece over that that would be longer and would help hold it in place.
Does anyone know, would it be possible for a good welder (not me 
) to remove the old raceway area and attach a new one without having to remove the whole headstock? Then I'd have to get it machined, ugh, this is gonna cost.
If you're going to swap out the original ball bearing setup with a tapered roller kit you may be in luck. I don't know how deep that bearing bore goes up into the headstock on a CB650 frame, but the bore on my 750K3 was pretty deep, I think it was near 7/10" deep but I'd have to check my notes to be sure, but it was way deeper than the bearing race needed it to be.
If you were to remove the old ball bearing races from the neck you'd have a much better look at just how much of the original bearing bore is still intact and how much is rusted away or compromised. Then slowly grind away the rusted bits and have a look and take some depth measurements to share with us.
From the frame number this is the 650?
I would shape up a new steering stop from thicker material and have it welded over the hole and then just file out the inner part where the weld is.
With a set of taper bearings you will have 95% support for the race on original bore and in my honest opinion for the power the 650 puts out that is way more than adequate
+1
[I really don't think this is dangerous, or else I wouldn't do it.
Some people jump out of perfectly good airplanes...so no issue.
It's your bike, so it's your call. Respectfully.
I didn't really follow what 754's plan involved, I need more coffee I guess.
But the website is
www.goallballs.com you can get them on ebay, you can have a local shop order them for you, it's a complete kit with seals bearings and maybe a few spacers. I hear they include directions now too! They usually run under $50, read Hush's install thread as it was thorough and recent, and was also on a 650.
I think you're gonna be ok, but I do have one question. When the PO layed the bike down hard enough to snap off the steering stop, was there any other damage to the frame? Were any welds cracked, was anything bent? If you've got other frame damage, finding another titled frame may be the cheapest and best solution, sometimes they're not expensive. ($50-150 range wouldn't be that unusual)
But seriously, I think if you get those old ball bearing races out of the neck, you'll be able to get a better look at how much of that lower race you've got to work with. Cleaning the rust off and patching it up will,as you have said, just keep the grease in and the dirt out, as well as restore correct function of the steering stop.
You probably won't need much, but good luck anyway.
-Alan
Here's a pic of the steering stop on my 750K3 frame for reference, I don't know what a 650's steering stop looks like.
