Honda Motorcycle Wiring Diagrams - Classic Honda CB750 Hondamatic CB 750 A Electrical Wiring Diagram Schematic 1976 - 1978 HERE. Honda CB750 K0 K1 CB 750 Electrical Wiring Diagram Schematic 1969 1970 1971 HERE. Honda CB750 K2 CB 750 Electrical Wiring Harness Diagram Schematic 1972 HERE. Honda CB750 K3 - K7 CB 750 Electrical Wiring Diagram Schematic 1973 - 1977 HERE Wiring Diagrams - oldmanhonda Wiring Diagrams. Here is a selection of wiring diagrams taken from my collection of manuals that may help get you through your electrical problems. CB400A 1978 Carburator and Idle - Total Motorcycle I recently got my hands a 1978 CB400A that has been sitting for years. I got it up and running, changed tires, fixed some wiring issues and changed the battery. Now I am running into an issue. It seemed that the throttle stuck one day when running a 6-8 mile jaunt.