I'm always seeking out new sources of new and used parts and will update this page accordingly. If you have parts for sale or know of parts sources and want to be referenced here, please send the information and I will add it. New parts are essentially impossible, and the best sources for used parts are ebay or the Honda 600 discussion groups on Yahoo, or the three experts listed below. The links to the yahoo groups are also listed below. Please note that I personally do not have any parts for sale, and am listing these contacts strictly as a convenience.
It appears that Kumho has stopped production of their 10" tire, and most distributors have sold out. There may be some information in the Honda 600discussion groups on Yahoo. See the links below.
The Yokohama A008 is available in 165/70-10 size for about $90 each. This is a high performance, soft compound tire designed primarily for autocrossing and other high performance applications. BUT - it is a quality, DOT-approved 10" tire. Tire Rack and other major tire retailers carry this tire in stock.
Listed here are other sources for new and used Honda 600 parts, plus part numbers and suppliers for parts that should be available at your local auto supply store. Please note that I haven't personally tried all of these sources, or personally verified all of the part numbers. However, the information is believed to be correct - please contact me if you find any of this information to be incorrect.
Classifieds from private sellers
None currently available
Links to other Honda 600 sites and groups
Other sites of interest to Honda 600 enthusiasts. The first two are great sources of actual expertise and parts.
Other interesting Honda 600 sites:
There are two Honda 600 discussion groups on Yahoo that are valuable sources of information from other Honda 600 owners. Many of the tips that I've included on this site came from messages on those groups. They are easy and free to join.
Honda 600 Part
Rear wheel cylinder
kits (2 seals and 2 boots)