In Love with the Honda CB400F

Honda's little four might be the best of the breed

honda cb400f 4

Photo by Nick Cedar

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1976 Honda CB400F
Claimed power:
32hp @ 9,000rpm
Top speed: 95mph
Engine: 408cc air-cooled SOHC inline four
Weight (with half tank fuel): 393lb (179kg)
Price then: $1,470
Price now: $2,500 - $4,500
MPG: 45-55mpg

Shelli Bohrer was grief-stricken. Her beloved Honda CB400 Four, lovingly cared for during eight years of ownership, was lying in the middle of the street, its frame twisted beyond repair after a teenage driver had plowed into Shelli on her way to the gym. The pulled hamstring and bruises would soon mend, but her Honda was totaled.

“I poured a lot of love and some money into that bike,” Shelli says. “I learned how to navigate San Francisco traffic as well as get nods from the Alice’s crowd. I learned to do bike maintenance on it. It wasn’t perfectly cherry, it wasn’t perfectly stock, but it was clean, reliable and fun. And it was my baby.”

Luckily, the driver had insurance. While Shelli’s lawyer was negotiating a settlement, an acquaintance named Nancy came into the motorcycle shop where Shelli worked, mentioned she was selling her Honda CB400 Four, and asked Shelli to buy it because she knew Shelli would take care of it. Shelli was torn. “Did I want to have that much emotional investment in a bike again?” Her girlfriend talked her into it.

Enter the CB400F
After the success of four-cylinder Honda CB750, Honda decided to build a complete range of motorcycles designed along similar lines. Honda’s first try at a small-bore four appeared in 1972 in the shape of the CB350 Four, a 347cc overhead cam with four carburetors feeding four very small cylinders. Impressively engineered, it was also seriously underpowered for its weight, and was pulled from the Honda lineup after two short years.

The next iteration of a smaller four appeared in 1975 in the form of the slightly larger and more sporting Honda CB400F. Like its predecessor, it had a single overhead cam, a single disc up front and four carburetors. Four uniquely curved exhaust pipes fed into one quiet muffler, and a new cylinder head with larger intake and exhaust valves pumped up power, as did boring the cylinders to 51mm from the 350’s 47mm.

Contemporary American motojournalists found the Honda CB400F problematic. Most street riders in the U.S. in the 1970s were young men. While a vocal minority advocated sporty handling, a majority of them were interested in straight-line power. A quiet exhaust note, reliable functioning, good brakes and lack of vibration were not hot selling points for a motorcycle in this era. To a quarter-mile obsessed public, what mattered was that for all its sophistication, the CB400F was no better in the quarter mile than the Yamaha RD350 and the Kawasaki 400 triple, the bikes it was usually compared to.

As a result, magazine testers tried to portray a mild mannered Clark Kent of a bike as something closer to Supercycle. They noted that when you wrung it out close to its 10,500rpm redline, the 408cc four wailed like a banshee. They pointed out that the CB400F was faster on the drag strip than a Suzuki GT380. And since the Honda was fitted with low bars, motojournalists proclaimed it was a café racer.

Despite the 400F’s failures in the machismo department, it was a well-built machine with technological innovations that aided ride-ability, including a nicely engineered six-speed transmission and a smooth, strong, low effort, slip-resistant clutch. A mild cam grind gave the engine good pull over a wide powerband — without the flat spots experienced by the two-stroke competition, thank you very much — and the CB400F was very stable in turns and accelerated nicely out of them.

Magazine testers praised the Honda’s functionality. It was, as one tester said, “a bike that delivers reasonable economy, comfort and exceptional performance in terms of speed and handling. There are flaws here and there, but the way the motorcycle handles most situations manages to reduce the quirks to minor annoyances.”

Among these annoyances was the fact the CB400F didn’t have enough room to carry two American-sized passengers comfortably. The seat was too hard and the bars bent some people’s wrists at an awkward angle, the horn was weak, and it was easy to accidentally kick the hinged right footpeg out of position.

Offsetting these issues, the Honda featured easy to read instruments that were well-lit at night, useful helmet locks, a wobble-free shift linkage, and a handy guard to keep the rider from catching a foot between the clutch cover and the brake lever.

All in all, it was a successful package, and Honda changed little about the 400F in 1976. For 1977 the low handlebars got higher and wider, the pegs lower and farther forward, and the seat somewhat lower, as well. Importantly, the engine and the suspension remained the same.

Four owners
Still, the CB400F didn’t sell well enough to make Honda happy. It didn’t have enough chrome to interest the cruisers, it didn’t look enough like a race bike to interest the sport riders, and it didn’t have enough horsepower to tickle the fancy of either set. The fact that Kaz Yoshima, a tuning wizard with connections to the Honda racing department, turned several into very successful racers did not enter the general consciousness.

Honda also may have considered the profit margin on this complicated little bike. It probably cost as much to build the 400 as it did the CB550 four Honda also started selling in 1975, and the 400 wasn’t as popular. Whatever the reasons, 1977 was the last year of the CB400F.

The virtues of this smaller four have continued to appeal to numerous enthusiasts, especially in Japan, where it has become a cult bike. Charlie O’Hanlon, owner of Charlie’s Place, a San Francisco repair and restoration facility for old Hondas, says the CB400F is the only old bike he ever sees on the street when he’s traveling abroad in both Tokyo and Paris.

Most American owners used the four as a commuter or as a weekend play machine, and many kept up the maintenance. As a result, a very high percentage of the 400Fs sold in this country have survived in good condition. “People keep coming across them,” Charlie says. “Just the other day, someone pulled one in great condition out of a garage.”

Shelli learned to ride on dirt bikes, but had never ridden on the street until she moved to San Francisco and made friends with the owner of a yellow Honda CB400F. Shortly afterwards, she found her own Honda four. “It was a ‘love of my life’ bike,” Shelli says.

Shelli left her CB400F home when a girlfriend proposed that they do a cross-country trip two-up on a Honda 750. As the trip progressed, they decided separate bikes worked best, so they found another 750 that had been sitting for eight years in the New Mexico desert. “Before I took that ride, the furthest I had driven a bike was about 20 miles,” Shelli says. “We broke down a lot and fixed our bikes a lot, and it wasn’t until we got to the state of Washington that the engine of one Honda blew up. We rented a van and trucked both bikes the last 800 miles.”

Shelli returned home and started collecting old Hondas; it didn’t hurt that she lived down the street from Charlie’s Place. “Twice my girlfriend Mary and I pushed engines on dollies from our house to his shop,” Shelli recalls. She and Mary learned to work on their bikes, and Mary rebuilt the engine of the blown up 750. The two started giving motorcycle maintenance workshops for other women interested in learning about their bikes.

Restoration
Despite owning other motorcycles, the CB400F continued to be Shelli’s main ride until the accident. After she bought Nancy’s four, she stripped all the hard to find original parts off her old four and put them on Nancy’s bike. Eventually, however, the transmission gave up. Shelli decided that this was a job for Charlie, so after selling a BMW she had tried — and failed — to like, she handed the proceeds from the BMW and the insurance money to Charlie, and told him to restore the 400.

Charlie is uniquely qualified to restore 400 Hondas — a modified CB400 Four is his daily driver. “Shelli basically had two bikes, one with a bad transmission and one that was badly wrecked. I’ve known Shelli for years, and she was going to do the work herself, but finally decided to give it to me. She loved that bike,” Charlie says.

Charlie started by tearing down the engine. “These engines are amazing. The bore and stroke are almost perfectly square. I rarely have to do as little to rebuild an engine as I do on a 400F. I replace the piston rings. I replace the cam chain and the cam chain slipper tensioner. Most of the time, the engine is beautiful inside,” Charlie adds.

“The cam chain tensioner is the Achilles heel of the 400F engine,” he continues. “With regular service, adjusting the chain, it’s no problem. If it’s let go, the chain will grind into the hinge of the tensioner. The amazing thing is that the engine will continue to run, and run well, even though the cam chain is slapping around and making a lot of noise. I’ve never seen a 400F break a cam chain. Fixing it is a pain in the ass — you have to split the cases.”

A lot of Shelli’s original bike survived the accident and was installed on Nancy’s frame, including the new-old-stock headers, found in a box in Arizona and unique to this model. “I’m amazed Honda didn’t do curved pipes on any other bike,” Shelli says, reflecting on their beautiful lines. David Silver in the U.K. makes Honda four repro parts, including the wheels now on this bike. “It’s so nice to see them with no scratches,” Shelli adds.

Charlie located a new front disc and adjusted the back drum. “The brakes are phenomenal,”  Shelli says. “The rear brake is still a drum, but Charlie made it brand new again. The electric starter now works. I got so used to doing the kickstart, I forgot I could use the electric start —  boy, is it nice.”

Contrary to period reports that 400Fs are cold-blooded, Shelli says her bike warms up quickly and makes a great everyday machine. “It’s quiet, a good city bike, but you could go cross-country on it. Sixth gear is good on the freeway, and the engine is so insanely smooth. Instead of the stock shocks, I’m using Hagon shocks. They give a very comfortable ride, even with my lower back issues.”

Since lots of people continue using 400Fs as daily drivers, Charlie suggests some minor work to ensure long term reliability. “Upgrade the charging system. Put in a modern regulator/rectifier. You should also rewire the bike — there is a lot of redundancy in the stock harness, and it draws off more electricity than it should. Replace the points with a Dyna S electronic ignition and you should have no problems,” he says.

Charlie also says he often rejets the carburetors. “A lot of fours have a #75 main jet. For some reason, they tend to run too lean in this microclimate. I change to #80s, and they run fine.” All other maintenance is routine — changing the oil (Charlie suggests 20/50 non-synthetic and changing it every 1,000 miles) and keeping the cam chain, drive chain and brakes adjusted.

“It’s a perfect city bike,” Charlie adds. “It’s cheap on gas — I get by on five dollars a week — and a crazy handler if the suspension is upgraded. It’s a light, quick bike, a bike people ride, even now, on a regular basis.”

And Shelli? “It’s so nice now, I’m scared to ride it,” she says. “I worry about parking it on the street. I’m just going to have to get over the first few dents.” And, of course, avoid another nasty accident. Shelli got lucky with this bike, but as she’s learned, good CB400Fs are getting hard to find, and after all the work she’s put into it, this one’s a keeper. MC 

Press reports
“Put bluntly, the most important thing about the new Honda CB400F is this: it’s really fun.” — Cycle, March 1975

“The ‘whoop’ sound produced when the 408 is doing its siren song at 10,000rpm is enough to convince anybody that Honda’s smallest ‘F’ is more than an ordinary two-wheeler.” — Cycle World, July 1976

“What Honda has done with the CB400F is capture a spirit. When café racing began, the idea was to have a nimble motorcycle with road-race components and legal equipment, for jaunts and fun and skill and all the other things which make us riders in the first place.” — Cycle World, May 1977

“The CB400F doesn’t teeter: it runs straight and true without a lot of help from its rider, and though it will respond quickly to control commands, it never comes up with any ideas of its own.” — Cycle, June 1977

Resources
SOHC/4 Forum
Charlie's Place 

Read more about the motorcycles mentioned in this article:
Honda CB750 Four: A Classic for the Masses
Honda CB400 Four: Less is More
Yamaha RD350 

tim
9/1/2014 9:51:51 PM

Great post!i'm thinking of buying 1 asking price $3k obo doing research to see what they're selling for.


michael andrade
9/11/2012 4:20:59 AM

love this article!!