1978-1982 Honda CX500 Deluxe Service Manual

Honda's CX500 earned its enduring nickname — "manure pump" — from its odd, air-compressor-like V-twin styling, courtesy of designer Shoichiro Irimajiri, the same engineer behind the GL1000 Gold Wing and the six-cylinder CBX. Reviewers were initially cold on the look, but the Deluxe, introduced in 1979 as one of three CX500 variants alongside the Standard and Custom, won people over with genuine engineering substance rather than styling flair.

Power comes from a 497cc liquid-cooled 80-degree V-twin, an unusual longitudinal mounting with the crankshaft in line with the frame — Moto Guzzi-style, not the transverse layout Honda typically favored. Four-valve heads are skewed 22 degrees to tuck the carburetors in tight, out of the way of the rider's knees, delivering a claimed 48-50 hp at 9,000 rpm and roughly 31 lb-ft of torque, run through a 5-speed transmission and shaft final drive — genuinely low-maintenance for the era. The CX500 also holds a genuine engineering first: it was the first production motorcycle fitted with tubeless tires.

The Deluxe distinguished itself from the standard CX500 mainly by dropping the original bike's distinctive fairing — nicknamed the "plastic maggot" for its unusual looks — leaving a cleaner, simpler headlight and instrument arrangement. Comstar wheels, a stressed-member engine hung from a steel backbone frame, and telescopic front forks paired with adjustable rear shocks rounded out the chassis. Dry weight sits around 441 lbs, with period testing recording a 106 mph top speed and genuinely strong 45-55 mpg fuel economy. Early production faced some reliability hiccups with the cam chain tensioner and alternator, though the platform built a loyal long-haul touring and commuter following over time.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a CX500 Deluxe's engine and driveline running the way Honda built it.