Honda CB 750 K (RC01) explained

Honda CB750K(Z)
Manufacturer:	Honda
Production:	1978-1982
Predecessor:	CB750 Four
Successor:	CB 750 K (A) CB 750 K (B) CB 750 F
Class:	Sport bike or standard
Engine:	743cc DOHC air-cooled straight four
Top Speed:	125mph
Power:	78hp @ 9000 rpm
Torque:	49lbf.ft @ 7000 rpm
Transmission:	5-speed manual, chain final drive
Suspension:	Front: telescopic forks Rear: swingarm with two spring/shock units.
Brakes:	Front 275 mm double disc / Rear 180mm drum
Wheelbase:	1520mm
Length:	2200mm
Width:	880mm
Height:	1160mm
Seat Height:	800mm
Dry Weight:	233kg (514lb)
Fuel Capacity:	20L
Fuel Consumption:	7.3L per 100km (100miles)

The CB 750 K(Z) (model RC01) is a motorcycle model by the Japanese vehicle manufacturer Honda.

The new 750

At the 1978 IFMA in Cologne the new CB 750 was presented as the successor to the CB 750 four for Europe and available for sale later that year. With a new DOHC engine design and numerous other new features it was presented as "what happens when you keep winning races".

New features

The DOHC 16 valve engine was based on the engine in the RCB943 and RCB997 featuring four valves per cylinder, and next to the timing chain driving the exhaust cam, a second chain driving the intake cam.^[1] The engine was also better balanced by moving the alternator from the left to the right side.^[2]

Next to the new engine, new features like the transistorized ignition system was promising smooth performance and greater economy. It had increased braking performance with double discs up front and a lower, deeply padded seat for greater riding comfort and handling.Increased suspension travel for the front forks and rear FVQ damper, and a taper roller bearing for the head for smoother riding.Improved safety features like an H4 headlamp and double rear brake light bulbs were also advertised.

Technical details

Sources:

Engine and power transmission

• Air-cooled 4-cylinder 4-stroke engine with chain driven camshaft (DOHC), 4 valves per cylinder (total of 16), via tappets actuated
• Power: 57 kW (77 hp at 9,000 min -1 .), Max torque 66 Nm at 7000 min -1
• Average piston speed : 2.07 m / s per 1,000 min −1
• Top speeds: 200 km / h (lying solo), 187 km / h (sitting solo), 179 km / h (with pillion passenger)
• 743 cm³ displacement with 62mm bore and 62mm stroke
• Compression ratio 9: 1
• Electric starter
• Contactless transistor-controlled battery ignition with mechanical centrifugal force adjustment
• Pressure circulation lubrication
• One-piece steel crankshaft with 5 sliding bearings
• 4 Keihin equal pressure carburetors with a diameter of 30mm
• Wet multi-plate clutch
• Constant-mesh 5-speed gear
• Three-phase - alternator (260 Watt at 5000 min -1), battery (12 V / 14 Ah)
• 4-in-4 exhaust system (sometimes shown as 4-in-2-in-4)
• Primary drive via inverted tooth chain
• Secondary drive via roller chain

Frame

• Double-loop tubular steel frame with a single-sided unscrewable support on the right for (dis) assembly of the motor
• Rear swing arm stored in plastic bushings (needle roller bearings from the end of 1980)
• Ground clearance 150mm
• Foot peg height 355mm
• Hydraulically damped telescopic fork at the front (35mm) with 160mm travel
• 2 hydraulically damped spring struts at the rear, springs adjustable in 5 positions
• Double 275mm disc brake with single-piston calipers at the front
• Simplex drum brake 180mm at the rear
• Comstar aluminum wheels with tubeless tires (3.25-19 / 4.00-18)
• 20L steel tank

Colors

The CB 750 K (Z) was available in four base colors: blue, black, red and brown.

Color code	Name	Implementation
R-104C-U	Candy Muse Red/Candy Burgundy	Metallic paint with gold or light red striping
YR-106C-U	Candy Bayard Brown	Metallic brown with gold striping (Canada only)
PB-107C-U	Candy Tanzanight Blue	Metallic blue with gold striping
NH-1	Black	Black with red striping

Notes and References

1. Honda Comes Back Strong . Cycle World . January 1, 1979 .
2. Honda CB750K, A Sophisticated Successor to Honda's Traditional 750 . Cycle World . January 1, 1979 .