Hi - First post, so may get it wrong (given I haven't seen similar posts). I've got an '80 XS650 I bought a couple years ago. Seemed to run fine when I bought it but I didn't drive it much until I replaced both dry rotted tires. Nonetheless, I've spent most of my time just detailing the bike, took apart the carbs, replaced from brake, small stuff. But, even though I've not put 100 miles on the bike, it continues to run worse and worse.
I'm not so cheap that I can't have it all fixed and detailed, but I bought this so I can work on it. But I have just learned, I'm not sure what I'm chasing or where to start.
So, right now I'm not looking for advise, I'd rather start by looking for someone in the Cincinnati area who can serve as my mentor...even in a paid capacity. If I can do the work, I'd rather.
Welcome JeffMc,
A good way to start is to make a dedicated thread for your bike. Stay in the thread with all your problems. Start with one thing and stay on it till the issue has been sorted.
Some time what looks to be electrical issues can be carbs and other times what look to be carb issues can be electrical. So it is best to start on the electrics and eliminate possibilities by diagnostics and working your way to the carbs.
Going through the loom on an old bike is the best thing, and first in my mind) to do. This makes sure that your electrics are 100% getting to where it need s to go. That means going through all connectors, both bullet, multi wire couplings and all switches, (bar left and right and ignition) and all
Earth/Grounds and cleaning them from corrosion, fixing loose or broken wires and replacing any connector that is disintegrating.
You may think because the bike was running ok doing a full loom clean up isn't necessacery. it is because full power from the charging system to the battery to the points is krux of the bike running properly.
A couple of links.
Start here XSleo explains this in a laymans terms
https://www.xs650.com/threads/what-happens-when-you-turn-your-key-on.9625/
great electrical guide
http://www.dansmc.com/electricaltesting.htm
A lot of problems people have chased through carbs have ended up being Ground/earth problems
https://www.xs650.com/threads/grounds-so-important.41775/
Gotta learn how to use
https://www.xs650.com/threads/how-to-use-multimeter.27826/
This will eliminate problems and also while doing those you get to learn about your loom/Harness the wires where to and the colours
https://www.xs650.com/threads/continuity-testing-made-easy.49917/
This is a great article on the harnesses and as it states...... Musings
https://www.xs650.com/threads/wiring-harness-musings.18925/
people have come on here with no mechanical knowledge, experience or tools and with the help from members on here they have stripped down their engine and rebuilt it, Especially the top end.
Pics are important to make sure we are all on the same page and as is with these bikes often parts have been swapped between yeas/models as with these bikes it is east to do. Not that it is bad or a problem but as an example from 1974 to 79 the carbs are BS38s but every 2 years the carb internas,l jetting and needles were changed, so there are 3 different set ups with the 74-79 BS38's.
1980-83/4 the carbs were changed to BS34's but if in the past an op had problems, he may have, or could have, changed his carbs from another year to his bike...........Again pics are important so we can help identify the area we are working on.
Bookmark the links i have posted, go and start a dedicated thread with some pics, stating your problems and history of the bike, whats been done to your knowledge, some info on yourself, especially any experience or capabilities mechanically.
Tech menu is good, can also use the search, (top right), as there is often tip bits can be gleamed that may not be in the Tech menu.
Anyways just an idea of what is on offer and some reading to get you started