Drewpy, that is good to know!
I know from experience the Candlepower replacement reflectors work great on '80 & '81 XS400s. Pre-'80 may be problematic as some have mentioned. I like using the SilverStar Ultra H4 55/60W bulbs. Bright white with great night visibility. I use these bulbs on all my vehicles, including my just sold motor scooter.