Nah I'm no expert. I have never done a PMA conversion so I will leave any comments on that to others. The PMA will not work with your TCI ignition system so you would have to change that also. You would have to put in the combined Mikes XS Pamco PMA kit or equivalent. that will be a couple of scheckles.
PMA/Pamco package 1980-84 XS650
PMA/Pamco package 1980-84. Kit contains one 24-2662 PMA unit (200 Watt) and one 14-0912 Pamco unit. Save $17 as a kit.
Permanent Magnet Alternator Kit (PMA) built specially for the Yamaha XS650.
Replaces your old rotor that has failed or magnet that has weakened over time. Replaces regulator/rectifier with solid state electronics. Fixes the weak link in the XS650.
Specifically built for the XS650. The PMA adapter bracket is hands down the easiest to use and best bracket available. It has the strongest rotor on the market to help with low RPM charging. The rotor hub is made with the correct keyway so there is no filing or guess work in getting the correct fit to the crankshaft. It has a plug and play voltage regulator with a battery side quick disconnect. Cannot be used with Yamaha (TCI) electronic ignition. They will need to use Pamco or Boyer Bransden Ignitions Systems.
The kit includes a laser cut voltage regulator mounting bracket that bolts to the rear upper motor mount bolts. Everything you need including all new hardware and step by step instructions are included in the kit.
Electronic Ignition Kit by Pamco, a proven reliable electronic trigger system
that replaces the stock XS650 breaker point type or factory Tci ignition and
is an easy set & forget system. This kit is for all 1980-84 North American model
650's that originally came with factory Tci ignitions or for any 650 that is in
need of all/most ignition system components. Fits: All 1970-84 XS650's.
Kit Includes: Basic trigger assembly (XS#14-0900) Auto Advance Unit, Advance Rod assembly plus additional 3 pc. 14-0653 locating pin, Cam Shaft internal bushings(3),Dual output XS performance Ignition Coil (#17-6903), XS Performance Yellow Silicone Copper Core Plug Wire set(20" each)(#23-2906) and Two 5K NGK Spark Plug Caps (XS#23-3113).
Provides increased reliability and serious (caution!) ignition spark to 75Kv.
Part #24-2671
$510.00 USD Kit
Or test all your charging components so you know if it's just a rotor you need, a rewound rotor will run you about 130.00 I would strongly suggest rewound from a reputable winder as there are some fitment issues with "new rotors" and your TCI pickups. Note; you need an 80-83 rotor because it has the magnet for the ignition on it. Since I am a collector I tend to just go out to the shed and "find" replacement parts for my own bikes. LOL