Retrospective: 1983-1985 Honda CB650SC Nighthawk

1983 Honda CB650SC Nighthawk
1983 Honda CB650SC Nighthawk. Owner: Bob Duncan, Atascadero, California.

This Nighthawk was truly a marvel of good looks and efficiency when it appeared in 1983. Good lines, good paint, cast alloy wheels, megaphone-styled exhaust and 65 horses out of an all-new 655cc in-line four. This middling-sized engine sported 16 valves, two overhead camshafts and hydraulic control of valve lash. With six gears connected to a trouble-free shaft drive. It seemed that checking tire pressures, occasionally changing the oil and keeping the bike looking shiny was all the maintenance an owner had to do.

“But wait!” cries a somber voice from a dark corner of the library. “Honda’s own ‘Motorcycle Identification Guide’ says there was a 1982 CB650SC as well.” Truth. So maybe we better start a little earlier. Like back in 1979, when the Japanese manufacturers were still wondering about what cylinder sizes sold best. Since the old Brit-bike 650s had sold well and were quite popular, the Big Four (Honda, Yamaha, Kawasaki, Suzuki) were all offering 650s—twins and fours. Honda came out with a very nice CB650C four-banger, 627cc, with single overhead camshaft, two valves per cylinder, and five-speed gearbox with chain final drive.

1983 Honda CB650SC Nighthawk
Just look at that ’80s-awesome dash!

After three years the marketing department felt the model needed a little more pizzazz. And a catchy new name—Nighthawk. But this 1982 Nighthawk used the old CB650 engine and chassis, with a new tank, bodywork and saddle. Would the new name and styling work?

No time to find out, really, because within a year an entirely new CB650SC Nighthawk appeared, which had obviously been in the planning when Honda gilded the old CB650 lily for the 1982 model year. It actually seemed that this was not a smart move, because the minor attention given to the styling gave the alphanumeric designation a hint of boredom. However, the 1983 model put the lie to that, getting rave reviews from everyone, everywhere.

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1983 Honda CB650SC Nighthawk
Dual slash-cut chrome pipes looked sporty.

As noted in the opening paragraph, the new 650 doubled the number of camshafts and valves. Each of the four cylinders had a slightly oversquare bore of 60mm, stroke of 58mm. For those interested in the minutia, the valves had an included angle of 38 degrees, with the intakes (28mm) enjoying 18 degrees, the exhausts (22.5mm), 20 degrees. For the average layman, these are just numbers, while for the engineer, these are essential for maximizing intake and output charges. And Honda made sure that the critically minded (motojournalists) knew all about this. Fuel was fed in via four 29mm Keihin CV carburetors.

The starter (operating through a self-adjusting chain running to the crankshaft) and alternator (discreetly cooled by a fan) were mounted behind the cylinders in order to minimize engine width—which was 16 inches, almost four inches narrower than the previous 650. Nothing stuck out to touch the ground should a sporty type want to see how far he could lean—unless he fell down. Another self-adjusting chain (getting rid of another onerous task) ran up between cylinders two and three to spin the cams. The crankshaft was one piece, and off the right end was the rotor that triggered the electronic ignition…all done with magnets, wrote one humorous reporter.

1983 Honda CB650SC Nighthawk
The Nighthawk had dual front disc brakes and cast mag wheels.

Primary drive was via a big sprocket (54 teeth) that sat at the left end of the crank, which spun an even bigger sprocket (92 teeth) inboard of the wet, hydraulically operated, six-plate clutch. The rider had a choice of six well-thought-out gears, which transferred power to the rear wheel via a shaft. After shafting the Gold Wing and the CX, Honda felt that this useful bit would be quite popular.

The drivetrain sat in a full-cradle, tubular steel frame—and was rubber mounted. Those annoying 10,000-rpm vibrations could barely be felt, leaving the rider to happily spin the motor up to redline. Showa supplied the suspension, with a 39mm fork up front, without air-assistance. However, the height could be slightly adjusted by adding air, while changing oil weight could alter the damping qualities. Rake was 28.5 degrees, trail, 3.9 inches.

A long, almost 20-inch, box-section swingarm ran out to a pair of shock absorbers that offered both rebound and compression damping adjustments, along with five spring-preload settings. Heavier riders complained about the shocks being too soft. “Go on a diet,” was the dealer response. Handling also suffered a bit due to the up and down jacking activity of the shaft, but only the sportiest of riders would find serious fault.

1983 Honda CB650SC Nighthawk
The Nighthawk was a surefire winner, and the name was resurrected in 1991.

The 19-inch front wheel carried a 100/90 tire, and two disc brakes with twin-piston calipers, providing excellent stopping power. The rear 16-incher had a 130/90 tire and a drum brake. Wheelbase was a shortish 57.5 inches.

It had performance, handling, styling, a 12.5-second quarter-mile time and a price of $2,800. Honda was sure it had a winner.

It did…in Europe. But less so in the U.S. The European rider tended to be more practical, and his motorcycle was usually his only transportation. But Americans were more focused on style rather than function, and were looking for very sporty bikes, or touring models, or the ever-popular cruiser. And in ’83 Honda was also offering the Interceptor, the Gold Wing and the Shadow. This “standard” did not cut the old Grey Poupon for the U.S. buyer.

We should note that Honda spread the Nighthawk name over a rather wide range of models, from the CB450SC 447cc parallel twin to the CB750SC 749cc in-line four. However, all Nighthawks were gone by 1986—only to have the name resurrected in 1991.

46 COMMENTS

  1. Man Oh man, I loved my ’83 Nighthawk 650! rode it 22 years, practically maintenance free. (except for normal oil change, spark plugs, brake pads, tires) I sold it and it still looked and rode great, but I wanted something with a longer wheel base that didn’t bump around my now somewhat aging bones. The young fellow who bought it, could not believe his luck. I miss that 6th gear!

  2. I am a proud owner of a 1985 Honda cb 650 sc nighthawk. It corners like a dream very little counter steering. Power is smooth and kicks in with an attitude starting at 3rd gear. Loads of power and 6 th gear keeps the rpms low and delivers 65 plus mph under 6K r.p.m I repainted it pearl blue and got rid of those long wobbly turn signals. New bigger hand grips, halogen bulb, starts with no choke in summer and can out run any 700 cc without even breathing hard. I ride it hard at 75 mph and never hesitates.

  3. I went to look at a V45 Magna in February 1983 and left with an ’83 650 Nighthawk. That bike was my sole transportation in 1983, 1984 and 1985. That bike gave me some of the best memories of my life. Absolutely loved it and it was as durable as they come and faster than many 750s.

  4. Is it difficult to find parts for and get these bikes serviced? My brother is advising me against purchasing a ’83 Honda Nighthawk because he says it’s bound to need excessive amounts of work on it on a regular basis and will be hard to maintain. I’m wondering if that’s true.

    It’s a beautiful bike. 39,000 km.
    $1900 canadian.

    What do people think?

    • My 1983 650 had minimal issues what so ever it was stone reliable no points shaft drive non issue there smooth quiet and for its day FAST ,hydralic clutch nice touch lightweight comfy seat , i am considering selling my 883 sporty to finance a good used nighthawk harleys vibrate less power only 45 ponys never disappointed with that honda .

    • Cb650s are awesome bikes and if it looks like it’s very well taken care of it will last you a lifetime! I wouldn’t pay 1900 for it unless it’s a concours resto. The only real issue with the CB’s in general is the starter clutch,which you cant get brand new but are rebuild able. Plugs, wires,and oil is pretty much the majority of required maintenance.

    • Lots of parts on Ebay for this model. You end up rebuilding stuff rather than replacing it. I own a 85 650. I do all the work on it myself and have found parts to be cheap and readily available. You must be mechanically inclined though.

    • Go for it!! I have an ’83 with just at 28,900 miles as of 3/7/2020, I have never had any issues except with the battery. I still have my original Shoei FM-2 sport fairing on it and recently repainted the bike a new Honda Accord dark Pearl Blue. Its Beautiful!! Never had any issues with motor, transmission, or drive. Shocks are worn a bit and front forks were rebuilt a month ago. I did replace the rotors on the disc brakes for more modern ones (slotted) and replace both master cylinder (clutch/ brake) new DOT 3 fluids and regular Amzoil Synthetic High mileage 5W-30. Newer tires are next, I may go to radials…maybe? I paid $1000 in 1985, because the carbs were plugged up. So buy one, you’ll love it. I do also have a ZRX 1200R, and a FZ1000R. I still ride the Night hawk to work almost daily!!

    • Je me suis acheter une en 2017 et j’ai fait faire une bonne mise au point et depuis je roule 5,000 km par année et elle va très bien mais je n’ai payé que $ 500 dollars, et avant j’ai eu une nighthawk 750 1982 pendant 13 ans et erreur je l’ai vendu, et je n’avais jamais de problème avec cette moto.

  5. I’ve owned almost every variable of the early to mid eighties motorcycle from all 4 of the major Japanese manufacturers. From KZ to GPZ, CB to CBR, XS to FJ, GS to GSXR. But one of my favorites is the 650 Nighthawk. I’ve had 4 of them, and they always impress, amazing ergonomics and comfort, after tweaking the carbs some of the best throttle response available, very impressive and linear power, and rock solid handling. This is one of the best kept secrets in motorcycling.

  6. In the process of giving a 1982 Cb 650 Sc ” barn find ” a restoration and new life. Had been sitting unused since around 84. Only about 1000 miles on it. This is a one year only bike..and cant wait to finish it , baby it.

    • dont baby it, ride the piss out of it and take it everywhere!
      find a decent set of top/side bags that come off and put together a small toolkit (metric sockets a small set of allens and a few pieces of hose fuel and the patcock vacuum) mount a usb charger and a phone holder and a hawk will take you across country in comfort.

  7. I’m about to start restoration on an 84′ cb650sc. It definitely needs work (needs gauges, headlight, battery, possible re-wiring, etc) I will take apart and bench test everything down to frame. If anyone has things I should keep in mind or watch out for please reply
    P.s. I’m getting the bike for 100$

    • have rebuilt 5 of these 4 from 1983 and 1 from 1984, if you have any hint that the crank case was split, take the time and split it. i applied 108 inch lbs and loctite to all the internal bolts as we had one back out and destroy the upper crank case. parts are plentiful on ebay and you can find new piston rings and a complete rebuild kit. other than that, enjoy!

  8. Important always grease the rear final drive when you take the rear wheel off. I had the unfortunate experience of being broke down on the highway. The splines and teeth will basically disintegrate and you will have no rear wheel drive. Also fill the final drive outer bolt attached to the hub with hydronic fluid. The starter is hard to find a replacement and I paid around 150 dollars for a rebuilt one. Also the bike should be on a trickle charger as it only charges after 2.5 or 3/ 1000 rpms. If you notice at a stop lights your front headlight will dim.

  9. I have a 1982 CB 650 sitti ng in my garage. Complete bike. I rode it for 8 years then parked it and bought a Ducati. I have completly rebuilt one of the same year that my cousin had. My bike is all original. I have great memories of it.

  10. My ’83 650 runs as good as the day I took it out of the showroom. Not a dink or dent on it, although I did run through a couple of break levers teaching my sons to drive it. One just turned 40 and I am giving it to him as a present. One funny story, at age 10, on the way back from a baseball game, he almost fell asleep on the way home. After that very scary moment, I made all of my kids sing…Rainbow Connection by Kermit the Frog whenever I took them places. No one had fallen asleep since.

  11. My first bike was a Honda Rebel that I bought used with a burnt clutch, which I fixed myself. It was a great learning bike but I outgrew the 250cc motor. I sold it 15 months later and then didn’t purchase anything until my cousin bought a 2016 CB300F. It reminded me of the great times I had motorcycling.

    Soon afterwards, I started the hunt for another used bike but I wanted something reliable. I didn’t want a sportbike and the backpain of crouching that comes with it. I didn’t want a cruiser again……so after many months, finally decided I wanted a Honda 919. But after seeing a lot of videos of how much power it had…..I decided to get something that would’nt put me in a hospital.

    So after looking at classifieds for a very long time……..I came across the CB650SC. It had everything I wanted…..a fuel gauge, shaft drive, hydraulic valves, centerstand,….etc…etc. I went to see quite a few in my area but I could tell it wasn’t cared for.

    Then finally………..I came across a mint condition 1984 beauty with 9K miles for sale on the computer, that I went the same day (in rain) to purchase. Best purchase of my life. Absolute mint……..great power……reliable. It just reminds me that I have to get out and ride.

  12. I just picked up an 85 for 200 bucks. Just under 6k miles on it, only catch is its been sitting in a garage for 15 years. Can’t wait to get it running.

  13. I’m looking at a ‘83 with 23k on it for 500$. Dude said it just didn’t turn over half a month ago. But the lights still turn on. Any ideas? Should I still buy it?

  14. I just bought an 84 nighthawk 650 a couple months ago as a starter bike, turns out it’s much more then a starting bike lol. Always looking to sell or trade though.

  15. Hi!

    1st time poster …

    My registration says I have a 1983 Honda CBX650E. Is that the same as a CB650SC?

    Sorry if that is a dumb question. I am new!

    Todd

  16. I have an ’83 CB650SC that I bought new and another complete one I bought for parts. Loved the bike’s looks and performance but carburetors are clogged. Has anybody successfully “unclogged” the carburetors or located replacement carbs?

  17. I purchased an 83 650 back in the late 80″s I had it for 3 years and rode it almost every day. It was by far the best motorcycle I have ever owned. I still kick myself for selling it.

  18. I’m about to purchase a 1983 nighthawk 650. The owner told me the oil pump is bad, but the engine still turns over. Could it be the oil pump chain or something else?

  19. My late son brendan would have bought this had he lived longer. He passed from pneumonia, had not had his pneumonia inocculation. PLEASE go get one, the only one you will need in your life.
    Brendan, all these good folk will ride their Nighthawks in your name I hope. He would have been 53 years on 12/25/19. Love Mom

    • For Phyillis, Godspeed Brendan.

      I am looking at one of these on CL Boston and find it attractive.

      I remember back in the day these were scorned as jumpy rear handling, short suspension with driveshaft weight. I also see adjustable rebound and compression damping, on the IEM shocks which speaks against bad suspension. I wonder.

  20. Having issues with it run when hot. Carbs are good checked them all. Re wired most of bike. After it cools down has no problem starting right back up. Someone help

  21. i bought a 1983 brand new at 17 years old and the bike was great. ran it hard and never missed a beat until I wreaked it 9 months later! fast forward 31 years i found a 1985 with 13k mi in mint condition and enjoyed for 3 years and I’m kicking myself for selling it. They are great bikes. if anyone finds one in great condition buy it an never sell it!!. I can’t find another one in the condition of my 85.

  22. I have an 84 650 nighthawk. Runs like a champ but when I turn the key on sometimes the oil light neutral light and tail light wont come on. My tach won’t work and I can’t see the gear I am in. All other lights work fine and it is legal even the high beam light works. It was working this morning then when I shut it off and then turn it back on after stopping somewhere this happens. Anybody have any answers to what it could be. I have tried turning it on and off over and over nothing. It will still start and run fine I just like to have my tach gas gauge and gear selector on. Any help would be appreciated.

  23. Could be the fuse block below the headlight bucket. I have an ‘84 also and replaced mine recently. The fuse holders for one of the fuses had broken and contact and naturally, continuity, was sporadic…

  24. I managed to buy one last year for 600 bucks. Just needed tires and a seat cover. I rid it almost every day and I love this machine.
    Poor guy practically gave her to me

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