I just put 30amp fuses in them since thats what the factory harness has in it. The biggest change in voltage from what I've seen on my bike and others is when replacing that 'black' voltage monitor wire from the R/R. Theres a major major progressive resistance problem in that wire somewhere. Someday I want to take the front end off and track that wire down to see exactly whats the problem in the wire from the ignition to the R/R. Mine has a major issue with about 9.3 ohms of resistance from the monitor wire to ignition, which was upping voltage output to 16V +. Since replacing that wire, I can remove the fuses from positive side running to the regulator to the battery to test it and it only causes a 0.6v voltage drop. So basically by rerunning that black wire to my battery allowing correct voltage monitoring, solve a lot of overcharging issues in that alone.
I seem to have somehow missed this thread for the last 2 months.
Jason, regarding the monitor wire, the schematic in the service manual is BS, take a look at the wire harness than Ken was nice enough to cut apart for me to see where the monitor wire goes... Farking nowhere.