Honda CB 650 (1978–1981) Review: The Refined Middleweight of the Classic Era
Introduction
The late 1970s marked a golden age for Japanese motorcycles, and the Honda CB 650 stands as a testament to an era when "Universal Japanese Motorcycles" (UJMs) ruled the roads. Slotting between Honda's iconic CB550 and the larger CB750, the CB 650 generation (1978–1981) offered a compelling blend of smooth power, accessible handling, and timeless styling. Even by modern standards, this air-cooled inline-four remains a compelling choice for riders seeking classic character without sacrificing usability. Let’s throttle through what makes this machine special.
Design & Ergonomics: Classic UJM Appeal
The CB 650’s design is pure 1970s Honda: a teardrop fuel tank with knee indents, a flat bench seat, and a no-nonsense chrome exhaust system. Its 770–780 mm (30.3–30.7 inches) seat height accommodates most riders comfortably, though the slightly forward-leaning posture (courtesy of mid-mounted pegs and low-rise bars) favors urban agility over long-haul comfort. At 220 kg (485 lbs) wet, it feels substantial but not unwieldy—a middleweight with a confident stance.
The analog dashboard is delightfully simple: a speedometer, tachometer, and basic warning lights. Fit-and-finish reflects Honda’s reputation for quality, with durable paint and polished engine cases that still gleam on well-kept examples. The twin rear shocks and 37 mm telescopic forks hint at its era-appropriate suspension tech, but we’ll get to handling later.
Engine & Performance: The Sweet Spot of Smoothness
The 626 cc SOHC inline-four is the star here. Output figures vary slightly between sources—50–63 PS (37–46 kW)—likely due to regional emissions tuning. Regardless, the engine’s character remains consistent: a linear powerband with a velvety rush from 4,000 RPM onward. Redline sits at a conservative 9,500 RPM, but the real joy lies in its midrange torque.
Throttle response is crisp for its era, aided by four 22 mm Keihin carburetors. The exhaust note is muted at idle but develops a sonorous growl above 5,000 RPM—a polite yet purposeful soundtrack. Cruising at 110–120 km/h (68–75 mph) feels effortless, though wind blast becomes noticeable without a fairing. Fuel economy averages 15–18 km/L (35–42 mpg), thanks to the 13.5–14.2 L (3.6–3.75 gal) tank.
Handling & Ride Quality: Predictable, Not Playful
The CB 650 isn’t a canyon carver by modern standards, but its chassis strikes a fine balance for everyday riding. The steel double-cradle frame feels rigid enough, while the 37 mm forks and twin shocks (preload-adjustable only) deliver a plush ride over bumps. Tire pressures matter: aim for 2.0–2.3 bar (29–33 psi) front and 2.25–2.5 bar (33–36 psi) rear, depending on load.
At low speeds, the 1,490 mm (58.7 in) wheelbase and neutral steering make it flickable in traffic. Push harder through corners, and you’ll notice mild flex in the forks and a tendency to understeer. The drum rear brake (on earlier models) requires a firm pull, but the front disc (single-piston caliper) offers decent bite. Modern radial tires would transform the experience—a worthy upgrade from period-correct rubber.
Competition: How It Stacked Up Against Rivals
Kawasaki Z650 (1976–1983):
The Z650’s DOHC 652 cc engine made 64 PS (47 kW), edging out the Honda in power. Its lighter weight (208 kg / 459 lbs) and sharper handling appealed to sportier riders, but the CB 650 countered with smoother vibration control and a more relaxed riding position.
Yamaha XS650 (1970–1983):
Yamaha’s 653 cc parallel twin offered vintage charm and easier maintenance, but its 50 PS (37 kW) engine felt agricultural compared to Honda’s refined four-cylinder. The XS650’s rigid frame also delivered harsher ride quality.
Suzuki GS750 (1976–1979):
Suzuki’s 748 cc inline-four made 68 PS (50 kW), positioning it as a "budget superbike." While faster, the GS750 was heavier (234 kg / 516 lbs) and thirstier. The CB 650 struck a better balance for daily usability.
Verdict: The CB 650 carved its niche as the most refined middleweight of its time—less aggressive than the Kawasaki, more sophisticated than the Yamaha, and more manageable than the Suzuki.
Maintenance: Keeping the Classic Alive
The CB 650’s mechanical simplicity makes it a favorite among DIY enthusiasts. Here’s what owners should prioritize:
- Valve Adjustments:
- Intake: 0.05 mm (0.002 in) cold
-
Exhaust: 0.08 mm (0.003 in) cold
Check every 3,000 km (1,864 miles). Use feeler gauges and MOTOPARTS.store’s shim kits for precision. -
Oil Changes:
- 3.0 L (3.2 qt) without filter replacement
-
3.5 L (3.7 qt) with filter
Stick to SAE 10W-40 (API SE or newer). Modern synthetic blends reduce engine wear. -
Carb Tuning:
Sync carbs every 6,000 km (3,728 miles) using a vacuum gauge kit. Replace OEM rubber intake manifolds if cracked. -
Chain Care:
The 104-link (or 102-link) chain demands regular lubrication. Upgrade to an X-ring chain for longer service life. -
Ignition Upgrades:
Stock points ignition works but consider electronic ignition kits for reliability. NGK DR8ES-L plugs (0.7 mm gap) are a safe bet. -
Brake Fluid:
Flush DOT 4 fluid annually. Swap to braided stainless lines for improved lever feel.
Pro Tip: Keep an eye on the air-cooled engine’s temperature in traffic. Retrofit an oil temperature gauge if commuting in hot climates.
Conclusion: A Timeless All-Rounder
The Honda CB 650 (1978–1981) embodies the best of 1970s motorcycling: approachable performance, mechanical honesty, and styling that never goes out of fashion. While it won’t outgun modern nakeds in a drag race, its creamy inline-four and user-friendly nature make it a joy to own. For riders seeking a classic that’s equally at home on backroads or café racer builds, the CB 650 remains a compelling choice.
Whether you’re restoring one or optimizing it for weekend rides, MOTOPARTS.store has the components to keep your CB 650 running smoothly—from NGK spark plugs to premium chain kits. After all, every classic deserves to be ridden, not just admired.
