rearenginekarts.com

... and they on used on many vintage karts and fun karts due to very low cost ($14-18 most dealers). There are older versions of this hub that are harder to come by, mostly cosmetically different. Why am I mentioning this, maybe I am missing something, but isn't that the same one Azusa is making today?

That's the one!

maybe the forth hole makes it special!!!
i think the new hubs have only three holes but otherwise are the same.
at these prices i have four or five old ones that i'll sell for 50$ each.but alas, they're used, maybe N.O.S. makes the difference???
dave

The main difference between the vintage ones and the current ones is that the vintage ones are actually somewhat round and run kind of true.

Clamp them on a piece of 1" round stock and take a light cut off them in a lathe.

Looks like the current version to me. The much older versions of this hub had round holes where the large openings are now (those openings were closed over with a hole in the middle). I think the original one dates back to around 1960.

Here is Azusa stuff at APS, hub is AZ-1872 (the Azusa part number):
http://www.apskarting.com/pdfs/190-202.pdf

and at APPOCO for the same price of $13.69
http://www.appcokarting.com/sprocket.pdf

Now here is another version of the hub, is this an earlier version or the current production version? Instead of 2 adjacent pairs of holes, it has just one large one (4 total).

I bought one from Azuza a few months ago and it looks just like the first eBay photo. Man did that person pay too much.

Thanks for the tip on truing it, I just assumed it was round and have not tightened it down on the axle as yet. I will check that out before It goes on permanently and true it up on the lathe if necessary.

ALso pay attention when you tighten the bolts. That can make it run off also.

...found this... one on far left is the earliest version I believe, it has the round holes. It is the one that came on my barn fresh 1961 Fox Go-Boy.