Honda CB400 Four: Less is More

More than 30 years later, the Honda CB400F has never looked better

| November/December 2006

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    Don Hughes' 1976 Honda CB400 Four.
    Photo by Robert Smith
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    Don Hughes' 1976 Honda CB400F.
    Photo by Robert Smith
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    Though the 400 Four sparked the café racer styling trend that would eventually give us today's repli-racer sportbikes, it wasn't universally appreciated at the time.
    Photo by Robert Smith
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    Photo by Robert Smith
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    Photo by Robert Smith

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Honda CB400 Four
Years produced:
Total production: 105,000 (est.)
Claimed power: 37hp
Top speed: 95mph
Engine type: 408cc overhead cam, air-cooled inline four
Weight (dry): 179kg (394lb)
Price then: $1,470
Price now: $1,800-$3,000
MPG: 45 (period test

More than 30 years later, the Honda CB400 Four has never looked better. A stalwart British bike fan, I’d never ridden a Japanese multi until one day in 1975. My “daily driver” was a persnickety BSA Victor, a worthy enough machine, certainly, but a real clunker. It was, after all, just an old-fashioned and only partially civilized dirt bike.

A friend offers me a ride on his new CB400F. I’m not going to like this, I tell myself. It’s a wussy rice burner. I’m still trying to kid myself that it’s nothing special when I hand it back. Just six years separate the Beezer from the F-bike, but the contrast is huge; it’s like the Space Shuttle just landed in the Stone Age.

I doubt I could have chosen a more stark comparison if I’d tried, and in spite of my own laggardness, by 1975 the rest of the world was used to four-cylinder Hondas. The Honda CB750 Four came first, of course, in 1969, and created the pattern for all Honda Fours for the next 10 years. The air-cooled in-line four cylinder wet sump engine used a chain-driven single overhead camshaft and breathed through four carburetors. The engine was constructed in unit with the primary drive, wet clutch and five-speed transmission. An electric starter was standard, as was the disc front brake.

Honda’s mini-multis
Having effectively created the four-cylinder category, Honda took its bag of tricks and downsized them. Next came the 1971 Honda CB500 Four, then the 1972 CB350 Four. This last machine exemplified Honda’s flair for miniaturization but was not a technical success. With four heavy chrome pipes, mild tuning and meager power, it was slower than the company’s same-size twin and barely capable of highway speeds. It nevertheless lasted two seasons on the back of the four-cylinder fashion.

From an engineering standpoint, the 1975 CB400 Four was a simple evolution of the 350. An increase in bore size from 47mm to 51mm combined with the 50mm stroke gave 408cc, and while the engine cases were changed to accommodate a sixth gear, many engine internals including the crank, rods and camshaft remained the same. Honda did revise the cylinder head, however, increasing compression to 9.4:1. Even the four 20mm Keihin carbs were retained.

6/13/2015 1:14:18 AM

Michael, I'm restoring a 400F and would love to have a good header for it. Don't know how to reply directly to you so if you read this email me at I'll be holding my breath! Gary

6/2/2015 5:40:49 PM

I bought one of the first four hundred/fours brand new in 1975, then rode it for a good ten years or so. It was a great little bike, but mine had a five speed transmission -- not a six speeder. I put flat dragster-style handlebars, and oil cooler, and a Kerker pipe on the bike, then rode the wheels off that thing. I finally sold it to a friend who was moving to New Mexico… but still have the original four-in-one chrome exhaust header. It's been in a closet for the past twenty years or so. Don't have the muffler -- that rotted off, thus prompting me to buy the Kerker header. It's in good shape, so if anybody out there is interested in buying it, reply to this e-mail.

1/8/2015 1:30:26 PM

A friend of mine--my employer at the time, about 1982--had a '75 400F Honda while I rode a '79 XS400 Yamaha. The Honda was soft on acceleration, rode no better, didn't stop as well as the XS. I had had the XS on a 4000-mile round trip to the west coast by that time, and lived to tell about it. The XS was probably the better bike... ...except for that wonderful four-cylinder smoothness, and the intoxicating four-cylinder wail. The XS twin was a paint-shaker by comparison--and of course suffered from Japanese Muffler Rot Syndrome, where the rearmost four inches of the mufflers fell off as though they suffered from leprosy--common for the late '70s/early '80s era. My boss and friend sold the 400F to buy a Gold Wing. I miss it. He doesn't seem to.

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