The smallest multi cyclinder put into production at the time, is why.
its a little like asking why did the Americans go to the moon? It cost a lot and the physical payback a couple rocks and some good photos. The psychological payback was why , it stamped Americas dominance of space on the Russian/ world psych. The 350f is the same it's a look what we can do bike

 

Interesting....now I want one.

 

Oddly, the 350F was less HP and slower/heavier than the twin too....But Honda also made smaller 6 cylinder engines...Honda's RC166 Had More than Met the Eye | Petrolicious

250cc, 6 cylinder....

Honda likes to show it's prowess in exotic machinery. They did a V4 with oval pistons....twin connecting rods on each cylinder....

Some really exotic stuff.

Mt favorite is the CB400 Four, though. It was one of the sexiest looking bikes when it was introduced. I couldn't afford a new one at the time, so I ended up with the CB360...but the little four was an object of lust for me. More so then the larger displacement 4's.

 

Richard: I always find it hard to understand the craze about the CB400F. Sure it looked great, but what was so ground breaking about it that people consider it one of the best bikes of that era? The 350F was the smallest 4 cyclinder motor Honda made and as far as I can tell, the 400F was just the next iteration of it. What makes it so special?

 

The 350 looks like a small 750. The 400 looked unique at the time. the 400 had no significant technology, but it was sexy looking.

Sent from planet Earth using mysterious electronic devices.

 

Hehe I guess looking sexy is good enough

 

Read about four cylinder, four stroke, 250cc Hondas made for the Japanese market. Their road tax treated bikes over 250 as large highly taxed bikes. Had different licence too. All I can remember from an article I read in the Philippines in the early 70s.

 

Find nothing about four cylinder 250 street hondas on the internet. Can't find out anything about two cylinder 50cc bikes from Italy I read about in the same article.

 

You're not thinking about the 1966 honda rc116 that was a 4 stroke 50cc twin with a 21000 redline

 

Good grief. 16 BHP @ 21,500 rpm. That's just an insane amount of hp out of 50cc's. My old 250cc bsa probably only put out ten hp even being five times the displacement.
Thanks for that info, Simo. Never new it existed.

 

To backtrack a bit, the 400/4 at the time really embodied the term "super sport". The looks were a huge part of that, but add to it rear-set pegs and one of the first 4-into-1 exhausts, and lower set "superbike" bars, and, I imagine, it would have been like buying a race-replica today.

Oh, and did anyone else catch the dry clutch in that 6? I want one!

 

Talking about want... I want to put a 1/2 set of the 350f or 400f CR Carbs on my build they're NICE!
got a 450? Hansen do a dry clutch setup Team Hansen Honda
or search HT someone's doing one on a 350t at the moment.

 

What an astonishing little machine!

 

Here's some more pictures of these little jewels
honda
I love the brakes....

 

400f is probably one of the nicest bikes Honda ever made, but, personally I found it just a bit too small so got a 550f
550f got all the updates 500f needed (except 6 speed transmission)
400f got 6 speed trans, stronger connecting rods (plus a few other things) and major re-styling compared to 350f
I have Photobucket account open, here's what happens to a 27bhp (claimed)350f when it gets a little bit over revved

 

Err.."Positive Crankcase Ventilation"....

 

I have a CM400T similar to that..........LOL

 

I always wondered why there is a 350 twin and a 350 four? Maybe there is a good reason that hasn't crossed my mind but why would they make the 350 four when the twin existed?

Why is it that General Motors built a 350ci V8, but when the Italians built engines of that displacement range, they were V12s?

My guess would be that those two I mentioned and those two you mentioned make their power at different RPM ranges. A 350cc twin is going to make its power much lower than a 350cc four (quad?). It might be easier to tune for a slightly broader powerband as well, at the cost of some higher-rpm power, but that's just speculation on my part based on observation of what they're selling. I would think that a (relatively) big-displacement twin would be better for a cruiser or farting around town in stop-and-go traffic and that an engine of the same displacement but more cylinders would make a better canyon-carver or race bike.

I'd also expect to see more transmissions with more gears on the smaller displacement per cylinder bikes to make use of what may be a narrower, peakier powerband.

Regards,
MDM

 

I have a 400f and when I compare it to by 450 I can see why Honda made the small fours. The twins might have more horsepower and they certainly have more low end torque, but the 400f is so smooth, and the six speed transmission is a perfect match.

Vibration is minimal and the little four wants to rev! You are shifting constantly, but that's the fun of these bikes. The 400 is a much more nimble bike than a 450 too - from pushing them around to riding, the 450 is a beast by comparison.

From what I've read a lot of people wondered why there were both twin and four cylinder 350's back in the day. The answer is that Soichiro wanted to build the 350, and it's claimed that this was his "favorite" of the 4 cylinder bikes.