Honda CB 350F



Make Model

Honda CB 350F




Air cooled, transverse four cylinder, four stroke, SOHC, 2 valve per cylinder.


Bore x Stroke 47 x 50. mm
Compression Ratio 9.3:1


4x Keihin 656 C, Ø 22 mm

Ignition  /  Starting

Max Power

34 hp @ 9500 rpm

Max Torque

2,79 m-kg @ 8000 rpm

Transmission  /  Drive

5 Speed    chain
Frame Simple tubular steel cradle, split under the engine

Front Suspension

Television hydraulic forks, 114mm wheel travel.

Rear Suspension

Dual chocks,   adjustable pre constraint (3 positions), 91 mm wheel trave.

Front Brakes

Single 260mm disc

Rear Brakes


Front Tyre


Rear Tyre


Dry Weight

160 kg

Fuel Capacity 

12 Litres


This Honda FOUR was initially intended to be two models: the CB250 and CB350 Fours. However, it was judged that the performance of a 250 would be disappointing, due to internal friction losses that were beyond the technology of the time. So only the CB350 Four was developed through to production.

As a miniature of the CB750 and CB500, the CB350 made a suitable entry level machine for North America as well as being suited to the European market. In spite of its small size, the CB350 was luxuriously finished with an upright riding position, four tilted-up silencers and chromium-plated mudguards. Although it attracted attention as the world's first four-cylinder production bike of such small capacity, the CB350 was not a big seller, probably because of its restricted performance and discreet styling.

Road Test Cycle 1973

Honda, as it has done so many times in the past, went on to monopolize the headlines with the new machine and brought flagging attention back on itself in one masterful stroke.

The newest four from Honda really borders on technological overkill. Like its 750cc and 500cc bigger brothers, the 350 bristles with beautiful touches. The engine, naturally, is the focal point for the motorcycle, and rightly so. Externally, it resembles its brethren, but the similarities stop there. The 350 Four shares little with the 500 Four and naturally, the 500 and the 750 really only have four-cylinders in common. The 350cc (actually 347cc) Four's engine is new from the cases up, although it is orthodox in relation to other Honda four-cylinder design concepts. That is, the powerplant is a transversely-mounted four fitted with a single overhead camshaft. Four 20mm Keihin carburetors feed the beast and exhausts are funnelled through and out four very nicely-shaped-andlocated mufflers.

The Honda mufflers bear further comment since they are extremely quiet in operation. It would take some spirited throttle work to scream the engine and make offensive sounds out the rear of the bike. In all types of riding, the mufflers purred out a mellow and melodic chuff-chuff. It definitely should not be a problem with irate neighbors or the local gendarmes. Score Honda high in the muffler department!

But now that we've got the engine sighing over neatly and it's warm, let's take a spin and look at several of the major reasons why, despite some faults and slight underperformance, Honda is going to sellout these new 350cc Fours.

At idle, the engine transmits virtually no vibration at all. It merely burbles away underneath you, waiting for action on your part. There is an interesting variety of noises discernible at idle; however, that can best be described as clatter. This is caused by the intricate workings of all those valves, springs, lifters, cam lobes and what not. It's an unusual noise, not bothersome at all, and makes you think that things are running very loose in the top end. A flick of the wrist brings more revs and the clatter tightens up and disappears and the engine begins to work with a turbine-like hum, a characteristic of the other two Honda Fours.

Engine noise, which has been snuffed out at the exhausts, has also been thoughtfully controlled at the intake end by the use of large plastic airboxes that serve to still the in-rushing air. Dry paper element filters are used and will probably suffice nicely in general street use, protected as they are by the voluminous air boxes. However, individual owners are going to be replacing the stock items with foam/ oil filters, as often happens. The foam/ oil units will work well but there might be a slight increase in intake noise with them. Nothing, we hasten to add, that will turn your new toy into a roaring beast, however.

Honda hasn't officially released any horsepower figures for the 350 Four as yet. Educated guesses put the figure at around 30, which is quite mild. After all, the Honda 350cc Twin road machine pumps out about the same horsepower and it doesn't have the mechanical sophistication of the Four. However, mechanical trickery doesn't always mean heavy horsepower increases. Sure, the new 350 Four has four cylinders, carbs and pipes, hut it also has more weight (total engine weight is around 135 lbs., meaning very heavy) and hulk and more power-robbing friction.

All of which means that, surprisingly, you're probably going to get more performance per dollar out of the 350cc Twin than this new Four. Really! But if it's performance that's guiding your purchase, spend a little more and get the 500 or 750. You see, the 350 is not a stoplight grand prix machine. It is fast and quick and responsive, but its long suit is in balance.

The 350 Four is a balanced bike. All its systems work in harmony and make it a joy to ride. Those 30 ponies do their thing through a butter-smooth, five-speed transmission. Gears engage with feel and when the clutch engages, you can tell because there's a little drivetrain snatch which is altogether common with Honda motorcycles. A little idiot light winks on to help you find neutral. The neutral light, incidentally, shares a small light panel with multi-colored lights for the high beam indicator, oil warning and turn indicators.

A year or so ago, an American firm started marketing a bolt-on accessory panel like this for Honda models so it looks like the factory has taken a cue from the U.S. market and has included its own idiot lights. The panel serves mainly to give the illusion of more sophisticated motoring. You could do without it. On the subject of instrumentation, the fine Honda speedometer/tachometer combination is rubber-mounted in tilted easy view. The speedo has odometer and resettable trip odometer and both worked smoothly and easily without any wild gyrations from the pointer needles.

But back to riding. With each cylinder displacing a tiny 87cc and all that machinery inside whirling and spinning, you can rightly surmise that the 350 Four is a high-winder. Torque buffs should go get a BSA Victor or even a 350 Twin. The new 350 Four just doesn't have any torque. But what it lacks in low-end pulling power, it makes up in spades when the throttle is twisted further and things begin getting together.

You feel the power building in a rush and it's very pleasant indeed. Each gear change serves to make the bike jet ahead even faster and you're absolutely flying by the time fifth is engaged. But we'd better bring back that concept of balance here before the power/ acceleration syndrome takes over. Sure, the 350 Four can move out with gusto. What's more impressive, however, is how it does it. A Harley-Davidson Sportster flat gets with it and little thought is given to how it goes about raising the hairs on the back of your neck.

With the Honda, how is almost more important than the mere fact that it performs quite well. The Honda has no mechanical whining or screaming to unnerve you. The mufflers don't emit a grinding bellow. Just a soft chuff-chuff-chuff-chuff coming in rapid-fire succession to let you know that you're getting with the program. Adding to the package of balanced power are the brakes and the spot-on handling. Perhaps we should say brake. Most of the bike's stopping ability is focused on the superb (funny how that word pops up in Honda tests!) 10 1/4-inch front disc. Hydraulically actuated, it brings rider and machine to an immediate halt and the rear drum unit, 6 inches in diameter, serves only as a backup, really. It is a super brake in the tradition of Honda discs and even features its own mini-splash fender to control water spray in wet weather riding.

The handling unifies the bike. The power and the braking are merely ideas until they are melded with the chassis—and what a fine-handling chassis Honda has come up with. Nothing particularly radical. Just a well-designed double down-tube cradle frame, finished in black with the usual quality Japanese welds evident. That is, a little on the cobby side but not had for mass production.

The 350 Four can easily breed overconfidence in a new rider. It handles that well. Yet, the easy power characteristics make it seem smooth and controllable. To dip into the four-wheeled world for a comparison: the 350 Four is like driving a Porsche. The bigger superbikes, like a highly-tuned Corvette, have oodles of horsepower and you almost feel like you're riding a guided missile. Not so the 350 Four. Just that Porsche smoothness and control. Very nice. Very civilized. Balanced.

The rest of the package serves merely to accent the engine, braking, handling. The current color scheme is a nicely applied maroon with white and yellow taped-on accent stripes that don't really look taped on. Chrome fenders are fitted. However, there's so much polished alloy all over the engine and those long, graceful chromed pipes that the fenders would probably he better if they were painted maroon. A little less flashy and gaudy. The seat is nicely shaped but a bit hard. Perhaps it was just newness.

And, damn it, Honda, when are you going to get your act together and put the ignition switch up on the control panel? That's right, the key is still stuck down under the tank on the left side of the frame. Dumb. A nice tool kit is included in a plastic tray under the seat but there is little room for anything else. The seat locks down to prevent thefts. Nice touch.

The handlebars are oddly-shaped but fall into place and did the job. Wouldn't clip-ons be nice as an accessory? Wow! The Federal government, in its infinite wisdom (actually finite!), has decreed that motorcycles shall have to have such and such lighting, this big and this bright and so on. Therefore, to satisfy Federal regulations, Honda has fitted a massive, cherry-red tail light that really breaks up the curves of the motorcycle. Your eye drinks in all the smooth, gliding lines and angles and then—bang—that tail light hits you in the mouth. Ugh! But don't blame Honda. Blame our own government officials.

Balance, then, is the key to the sales story on this latest product from Honda. It isn't the fastest Honda, nor really the fastest 21- incher on the highways. It's a bit overweight and the price will probably fall around $1200 out the dealer's door. But they'll sell 'em. Partly because the name Honda is on 'em, and mostly because the 350cc Honda Four is an excellent motorcycle.

Source Cycle 1973