[embee]

The favourite fix is to fit a MOSFET type from another bike. The MOSFET semi-conductors inside the reg/rec have a significantly lower volt drop across them and so don't heat up as much, and they are much more reliable and stable than the original R/R.
They usually have a code number like FH012, FH014, FH020 etc., generally the higher the number the greater the capacity I believe, a 14 or 20 would do fine.

I fitted one to my curvy, IIRC it came from a Honda ATV (ebay). You will need to alter the wiring, but it is very simple to do, the yellow alternator wires are all the same, and there are just the pos and neg outputs. The FH MOSFET R/Rs usually have two sockets on them, one with 3x1/4" spades for the alternator, one with 2 spades for the output. The pos/neg are always the same way round as far as I know, a search will come up with which is which, the pos is the inboard spade, the neg is the outboard one. Search Shindengen mosfet reg/rec on google images and you'll find it.
Later versions have slightly different sockets to the earlier versions.

This ebay item 193208402423 is an example, or 163663042100 , or search for cheaper alternatives. Just found this one, cheaper 143492606641