The bike is a 97 M900, the bulbs are 55w each on low beam and 60w each on high. Should I unplug one bulb until I upgrade the charging system?
You can't really upgrade the charging system without changing the crankshaft, side cover, stator and rotor. The side cover is also different, as is the regulator.
I believe the wiring is the weakest link.
I run an 80/100w bulb in my bike and have had
no problems at all. Just make sure all the connections are clean and tight and don't worry about it.