SeattleKZ wrote: What are the stock tire sizes for a 1976 kz900?
Per FSM:
Front -- Dunlop
F6B 3.25H-19 4PR 28 psi (rider only) 28 psi (rider and passenger)
Rear -- Dunlop K87MKII-M
4.00H-18 4PR 32 psi (rider only) 36 psi (rider and passenger)
4PR means
4 Ply Rated.
Good Fortune!