Honda CT90 Ranch Wiring - Home of the Pardue Brothers Some years ago a farmer wrote us about an old CT90 sitting around unused. Varmints and time had ruined the original wiring, but the engine and chassis were serviceable. He knew if he could rewire the bike using parts store wiring and toggle switches, it would make a great bike for riding the fences. Honda CT90 with Lifan 12 Volt Engine Wiring Diagram Honda CT90 with Lifan 12 Volt Engine Wiring Diagram $ 4. This is Jon’s full color zoomable high resolution diagram. Printable. Includes wiring for kill switch relay, 12 Volt regulator, and CDI. A must have for clone engine installations and custom builders.