Editing Honda CB550SC

{{DISPLAYTITLE:{{PAGENAME}} Nighthawk: history, specs, pictures}}
{{Infobox Motorcycle
|name             = '''Honda CB 550 Nighthawk'''
|image            =
|aka              = 
|manufacturer     = [[Honda]]
|parent_company   =
|production       = 1983 - 1984
|model_year       =
|predecessor      =
|successor        =
|class            = [[Standard]]
|engine           = Air cooled, transverse four cylinder, four stroke, SOHC, 2 valves per cylinder
|bore_stroke      = 58.4mm x 58.4mm
|compression      = 9.5:1
|top_speed        =
|power            = 74.96 HP (55.9 KW) @ 9500RPM
|torque           = 27.29 ft/lbs (37.0 Nm) @ 8000RPM
|fuel_system      = 4x30mm Keihin carburetors
|ignition         =
|spark_plug       = {{sparkplug|NGK DPR8EA-9}} '83
|battery          = {{battery|YUASA YB12AL-A}} '83
|transmission     = Gear box: 5 Speed <br>
Final Drive: Shaft <br>

|frame            =
|suspension       =Front: Telescopic fork <br>
Rear: Swing arm
|brakes           =Front: Single 320mm disc <br>Rear: Drum
|front_tire       = {{tire|100/90-19}} 
|rear_tire   	  = {{tire|130/90-16}} 
|rake_trail       =
|wheelbase        = 56.69 inches (1440 mm)
|length           =
|width            =
|height           =
|seat_height      =
|dry_weight       =
|wet_weight       = 207.0 kg
|fuel_capacity    =
|oil_capacity     =
|fuel_consumption = 4.90 litres/100 km (20.4 km/l or 48.00 mpg)
|turning_radius   =
|related          =
|competition      = [[Kawasaki KZ550H]]<br />[[Suzuki GS550E]]
}}

The '''[[Honda]] CB 550 Nighthawk''' was a Air cooled, transverse four cylinder, four stroke, SOHC, 2 valves per cylinder Cruiser [[motorcycle]] produced by [[Honda]] in 1982. It could reach a top speed of 116 mph (186 km/h). Max [[torque]] was 26.92 ft/lbs (36.5 Nm) @ 8000 RPM. Claimed [[horsepower]] was 73.35 HP (54.7 KW) @ 9500 RPM.  


==Overview==
This is a 550 Four performance cruiser, factory rated at 75 bhp at 9500 rpm, 36.5 lb.-ft. at 8000 rpm. Potent [[air-cooled]], [[DOHC]], link-plate cam chain, four valves per cylinder, offset [[rocker arm]]s with hydraulic lash adjusters, plain bearing crankshaft, helical [[primary gears]], hydraulic multi-plate wet clutch, six-speed transmission, shaft final drive. 

This is the smaller version of [[Honda]]'s 1983 inline Four, introduced in the Nighthawk 650 and Nighthawk 550 for 1983. The engines share crankcase castings, clutch, transmission and cylinder head. The 572cc 550 has lower primary gearing and the same 60mm bore as the 650; stroke is shorter; 50.6mm to 58mm. To work with the 50.6mm stroke, the 550 has shorter [[connecting rod]]s, crankshaft throws and cylinders. The crankshaft, designed for the 572cc version, is lighter with 1mm smaller diameter journals; the cases are machined to fit.

The engine is designed to be compact. It is narrow, the alternator mounted behind the cylinders, overdriven off the crankshaft by a link-plate chain. It is short; the transmission shafts staggered vertically instead of laying one behind the other. It's also designed for low maintenance. The hydraulic lash adjuster automatically take up clearance between valve stems and [[rocker arm]]s - meaning no valve adjustment is necessary - and pump down if the engine is over-revved, increasing clearance and reducing the chances of a mis-shift bending the valves. The transistorized electronic ignition is not adjustable, and has electronic advance. The hydraulic clutch, like hydraulic disc brakes, is self-adjusting.

Low maintenance doesn't mean low performance. The 550 has the same cams as the 650, and, used with the smaller engine, those cams are closer to the high-performance grinds sold by aftermarket engine builders than are most stock camshafts. The four [[Keihin]] CV carbs have oval throats, 26.8mm at the [[venturi]], 30mm at the throttle plate, with lightweight throttle slides and thin [[diaphragm]]s for instant throttle response. Combine the cams and the carbs with the lighter crankshaft and you've got a quick-revving, free-winding 550 that feels faster than anything in the class.

It feels fast because it has a big jump in horsepower and acceleration at 7000 rpm, gaining engine speed from there at an astonishing rate right up to the 10,000 rpm [[redline]]. It pulls well from 4000 rpm, well enough to leave lights quickly and have fun gaining speed, but then there's that kick at 7000 when the Nighthawk comes on the cams, and off it goes. There's nothing to distract the rider from that magic rush of the tach needle toward redline, since the rubber-mounted engine is one of the smoothest ever put in a motorcycle. That glass-smoothness adds an eerie quality to the soaring tach and the kick-in-the-pants acceleration.

Slam the 550 into second gear at redline and the front wheel comes up and floats a foot or two off the ground, slowly settling as the bike continues to gain speed. Keep the Nighthawk near the redline, shifting quickly, and a rider on anything short of a sporting 1100 will have to work to keep up or pass. Street impressions send a strong message, that this is the most potent, quickest, fastest 550 around.

A trip to the dragstrip brought some surprises. The Honda Nighthawk isn't the fastest 550, with a best pass of 12.64 seconds and 102.27 mph. That's about as fast as a [[Kawasaki KZ550H|1982 Kawasaki GPz550]] and not as fast as a 1983 [[Suzuki GS550E]], even though the Nighthawk feels quicker than both.

The Nighthawk's tall sixth gear is made for highway cruising at a leisurely pace, bringing engine rpm at 60 mph down to 4400 rpm from fifth gear's 5200 rpm.

==Engine==
A 58.4mm [[bore]] x 58.4mm [[stroke]] result in a [[displacement]] of just 572.0 cubic centimeters.  

==Drive==
The bike has a 5 Speed transmission.  

==Chassis==
It came with a 100/90-19 front [[tire]] and a 130/90-16 rear tire. Stopping was achieved via Single 320mm disc in the front and a Drum in the rear. The front suspension was a  Telescopic fork while the rear was equipped with a Swing arm. The wheelbase was 56.69 inches (1440 mm) long.  


==1983==
<gallery>
Image:1983_honda_Cb550sc.jpg|1983 Honda Nighthawk 550
Image:1983-Honda-CB550SC-Black-0.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black-1.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black-2.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black-3.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black-4.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black-5.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black1-0.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Black1-1.jpg|1983 Honda Nighthawk 550 (CB550SC) in Black
Image:1983-Honda-CB550SC-Red-426-0.jpg|1983 Honda Nighthawk 550 (CB550SC) in Red
Image:1983-Honda-CB550SC-Red-426-1.jpg|1983 Honda Nighthawk 550 (CB550SC) in Red
Image:1983-Honda-CB550SC-Red-426-2.jpg|1983 Honda Nighthawk 550 (CB550SC) in Red
Image:1983-Honda-CB550SC-Red-426-3.jpg|1983 Honda Nighthawk 550 (CB550SC) in Red
Image:1983-Honda-CB550SC-Red-426-4.jpg|1983 Honda Nighthawk 550 (CB550SC) in Red

</gallery>


The Honda Nighthawk 550, designated CB550SC'83, was sold in 1983. Two colors were available: Candy Presto Red and Black. It had a chrome rectangular headlight and a 4-into-2 exhaust system.
*Engine: Completely new compact 572cc, [[DOHC]] inline four-cylinder
*Power: 64 horsepower
*Valve train: Hydraulic Valve Adjuster system, 16 valves
*Transmission: 6-speed
*Drive: Shaft
*Clutch: Self-adjusting Hydraulic
*Suspension: Air-adjustable front forks with integrated fork brace
*Oil: Oil cooler
*Wheelbase: 1440mm (56.7 in)
*Seat height: 777 mm(31.1 in.)
*Fuel capacity: 12 liters (3.2 gal.)
*Weight: 191 kg (421.1 lb)
*The serial number began JH2PC0901DM000023

==1984==
[[Image:1984_honda_Cb550sc.jpg|left|thumb|1984 Honda Nighthawk 550]]
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The Honda Nighthawk 550, designated CB550SC'84, was sold in 1984.
*Engine: Completely new compact 572cc, [[DOHC]] inline four-cylinder
*Power: 64 horsepower
*Valve train: Hydraulic Valve Adjuster system, 16 valves
*Transmission: 6-speed (5-speed plus [[overdrive]] sixth)
*Drive: Shaft
*Clutch: Self-adjusting Hydraulic
*Suspension: Air-adjustable front forks with integrated fork brace
*Oil: Oil cooler
*Wheelbase: 1440mm (56.7 in)
*Seat height: 790 mm(31.1 in.)
*Fuel capacity: 12 liters (3.2 gal.)
*Weight: 190 kg (418.8 lb)
*The serial number began JH2PC0901EM000023

{{motorcycle-stub}}
{{Honda CB}}
{{Honda}}
[[Category:Honda motorcycles|CB550SC]]
[[Category:1980s motorcycles]]
[[Category:Honda Nighthawk series]]
[[Category:Honda CB series]]
[[Category:Standard motorcycles]]