Hello Ray.
I had to do the cam guide on my '78 SE at 21,000 miles, (34,000km). I honed the cylinders and re-used the original pistons with new standard rings. I have replaced or rebuilt most of the electrical system including the ignition/charge elements though I have retained the points and mechanical advance. The old girl hums like my granny's Singer sewing machine.
The support here is excellent and you can be assured that you will find step by step instructions for completing virtually any task. If you can provide photos, you will get specific assistance with everything from mechanics to electrics. I do have an excellent mechanic here on the Coast as backup if times get hard. "Macca", at Pro Power did his apprenticeship on XS's and has helped me with the finer points of tuning. He lights up every time I ride into his shop and has provided invaluable advice.
As for parts, there is Geoff's as well as the XS 650 Club. On the Coast, a fellow named Peter Mercer runs Robina Wreckers and often has good used parts in stock. He is a former English race rider with a wealth of XS experience. A bloke called Peter Kommer used to carry XS parts out of Sydney or Melbourne but I don't know if he is still operating. The market place here on the forum is, also, a reliable source of parts. Sometimes, you just have to use Mikes though the jury is out on quality as most of his bits come from China. Mikes rubber items are not particularly durable from my experience but you can still source many OEM bits from Yamaha, Partzilla or CSMN. Then there is always eBay. You have already dealt with Skull, a compatriot who is a wealth of model and historical info. Geedubya and Flea are Australian forum members with experience on this bike from an Aussie perspective.
Yours is a 77D if I recall correctly - considered by many to be the best of the lot, (I prefer the SE - don't know why). The XS is a relatively simple machine and you will be successful if you do your research and follow Forum advice.
Shipping costs and wait time are our great disadvantage here in Oz. I am currently looking at a part from the States that I anticipate il cost up to 6 times its purchase price in postage costs. I either get it and ride or don't get it and walk. Easy choice. Over the last 4 years I would have spent at least half my money on shipping. Buy everything before you start a job and have it on hand so that you can work uninterrupted on its completion. It's also a good idea to buy 2 or 3 of the consumable items to allow for the inevitable error - don't know about you but I am not a mechanic and I hate sitting around on a beautiful riding day waiting for new sump gaskets or push rod seals to arrive.
If you have a new cam guide in place, you may not need to pull the motor for a few miles yet. Ongoing maintenance, (despite Gary's pointed sarcasm), is the key for successful XS ownership. Many PO's have performed backyard abortion mechanics on these bikes or ignored them entirely - which is where Gary is coming from.
Keep an eye on the valve adjustment, timing chain tension and oil filters. Keep the carbies clean, synced and air tight. You'll be fine. Enjoy the ride.
Cheers
