Sure, because the tank isn't 400ccs, it's closer to 4 gallons.
BTW, 1975 CB-750K owner, plus had a 1982 CB900F. Two great hondas. When the 750 worked, I used to take it onto unpaved logging roads and just spend hours cruising through the woods. The low center of gravity and good mid range torque made it perfect for those roads, without the discomfort of a two stroke chainsaw-attached-to-rearwheel dirt bike.