As relayed to me when I had a similar query, the 2001+ stator is rated/documented for between 150W and 170W, and supposedly the earlier ones have the same part number, so it should be reasonable to assume they're in the same ballpark.
If you want the best bright-for-the-(wattage)buck, LED is the way to go for sure. I have my rear converted, with the front sporting a LED drop-in bulb replacement that is better than stock and stock turn signals. Next step for me is to finish the CAD and send it to my 3D printer so I can mount the Truck-Lite 7" round headlight, the LED turns, and separate LED running lights.
Apparently this is from the old version of this forum, and the posts haven't been migrated or some sort of situation like that:
Stator rewind for higher output? - Yamaha TW200 Trailway Discussion Forum
(note the URL being /forums/ rather than '/forum/')