This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This 1973 Honda CB500 was acquired by the seller in April 2017, reportedly after sitting in the shed of its second owner since 1983. The bike has since been refinished in silver and fitted with a later 544cc SOHC inline-four featuring a CB650 camshaft, ported and polished cylinder heads with oversized intake valves, a custom-built Pasolini replica exhaust system, electronic ignition, and more. Shifting is through a five-speed manual transmission, and additional modifications include a Yamaha R6 front end, Ikon rear shocks, Lester mag wheels with Avon tires, a Speedhut digital gauge, and more. An oil change and valve adjustment were completed approximately 200 miles ago. This CB500 is offered with a tool kit, an owner’s manual, a magazine featuring the bike, and a clean South Carolina title in the seller’s name.
The fuel tank and side covers were refinished in a shade of silver reportedly exclusive to the Japanese market, with the former receiving painted-on black stripes similar to those on a CB450. The frame and swingarm were powder-coated black, and much of the hardware was replaced. A new old-stock seat was fitted along with smaller turn signals, reproduction tank badges, and replacement side cover badges. Chrome accents include a Harley-Davidson front fender as well as a CB350 taillight bracket and rear fender, with the seller noting a yellow hue to the latter.
Vintage Lester seven-spoke mag wheels wear 100/90-19 front and 110/90-18 rear Avon RoadRider tires said to have been replaced during the refurbishment. Suspension includes a rebuilt 43mm conventional front fork from a Yamaha R6 installed with custom wheel bearings and spacers. Ikon shocks are fitted out back, as are new bronze swingarm bushings and inserts. The steering stem bearings were also replaced.
Handlebars and foot controls from a CB400F were fitted in addition to a Honda Racing-branded Speedhut digital gauge with a 120-mph speedometer and a 12k-rpm tachometer that is said to be inaccurate at higher RPM. Just under 1,300 miles are shown on the digital odometer, with total mileage unknown. A replacement wiring harness was fitted during the work.
The replacement 544cc inline-four is from a later CB550 and features a ported, polished, milled, and vapor-blasted cylinder head with a CB650 camshaft, 1.00mm-over intake valves, and replacement exhaust valves. Induction is from four rebuilt Keihin carburetors, while the hand-crafted exhaust is modeled after a Pasolini racing system. The engine also features polished covers, an electronic ignition system, and an AGM battery.
Power is sent to the rear wheel via a five-speed manual transmission and chain drive. An oil and filter change, valve adjustment, and timing check were performed approximately 200 miles ago. An idling and revving video has been provided by the seller.
A tool kit and an owner’s manual are included in the sale. Photos taken throughout the refurbishment can be viewed in the gallery along with a Vintage Japanese Motorcycle Magazine article featuring the bike. A start-up, walk-around, and riding video is provided below.