Topic: 400 - 4 Supersport

[gregk]

Need some imput from 400 owners.  I have a chance to pick up a 400 - 4 Supersport, 75 or 76 I think.  I am attracted to this bike because it looks just like my 76  750 Supersport right down to the color (yellow) only smaller! 
The bike has been neglected but appears to be all there with the exception of one side cover. 
 what are the problems or weakness with this model, if any?  How about parts availability?  Might make a neat cafe racer.

Greg

[Ted Nomura]

The yellow CB400F, if it's original, is a 1976 model. I have the same model. If the gas tank have a recessed hatch, then it's a 1977. Check the frame number. If it starts with 1, then it's 1975, 2 is 1976. My CB400F was manufactured in July 1975, but it's a 1976 model.
Since CB400F is a collector's model, you can find part for it relatively easy but not cheap. Check ebay first then CMSNL.com. The latter sells near perfect reproduction parts for many Honda Fours that are often better than originals. Their CB750 side covers are superior since originals are now brittle and easy to crack. I've seen many terrible custom CB400Fs. It's best to make yours as stock as possible. Next to my CB750 and CB500 Fours, it's the best and most fun to ride.

[GroovieGhoulie]

Weak parts:

Camchain tensioner is not so good.

Other than that, it is probably the best SOHC in Honda's lineup, tied only by the 1969/70 750.

[supersport_CB400F]

Don’t touch it …piece of #$%* bike get another 750 

[Zane]

I love mine.

If you weigh less than about 165, buy two of 'em.

I've heard from a lot of sources that the cam-chain tensioner is a design flaw (no problems with mine yet, however -- knock on wood).

I've also heard the silicon rectifier can go relatively easily.  They list for almost $300. (CAN), but you can find good ones for 10 to 20 bucks on Ebay.  (After mine went, I bought two excellent used ones for thirty bucks, total.)

It seems the seat can loosen up (leading to a cracked pan) but that is fixable by restoring the rubber pads to original or even a tad larger than original clearances.  The trick is to shim it with the pads enough so it doesn't rock at all under load.

It can be hard to find a bike with good, fresh looking and well functioning gauges as well.  I think many owners just never got (get) it about keeping cable lubrication well away from the magnets in the gauge guts.  Even the littlest bit of oil or grease sitting on the magne for thirty years will corrupt it to some degree.  The needle gets jumpy with that stuff on the magnet, but if the magnet is corroded in the least amount, the needle will stay jumpy even if you suspended the entire cable in oil or grease. (Not that you could do that...)

Mine is so fun, I have yet to experience even the most remote pang of regret about purchasing the machine.  It is, despite the odd frustration with my own riding and mechanical abilities, more fun than everything.

Good luck ....

[Vagelis]

I've had mine for 18 years now. A daily driver (365 days a year, since winters here in Greece are not that cold). Has never left me out in the middle of the road. The cam chain problem that everyone talks about is fixed quit easy. Chances are it will get noisy after about 10,000 miles, Just change the slides and that's all. I've done over 30,000 miles without a slight noise!! About the rectifier, that's a problem. Especially if go to electronic ignition. I cured the problem by making my own rectifier. Easy and cheap. Just go the electrical forum on the cite and you will find my post with everything you'll need. If you need any help just email me. I've had it on the bike now for 7 years with no problems.
Ride safely, Vagelis

[gregk]

Survey says:  yeas 4 nays 1. The yeas win.  I'm going to buy it.  I'm also a bit confused by biffta's comment as he has a 400 on his avitar?  I am also going to restore the bike.  That way it will look like "mini me" beside my 750.  The tank has a flush fuel latch so must be 76.
Thanks for the information.  Wish me luck.

Greg

[supersport_CB400F]

Hey Greg, I was joking with you     they’re more fun to ride around on than you could imagine……….

[GroovieGhoulie]

Yeah, don't take biffta's comment seriously.  He's one of the 400F Cult members on the board.  The bigger bikes are great and I want some, but there is truly something magical about that little mini-multi.  I can't describe it, but that little machine really is special.  Honda hit a grand slam with that one.

People don't believe me when I say I have a 400 four-cylinder.  They cannot believe that it takes four pots to spin only 400ccs.  I just don't have the heart to tell them about Honda's six-cylinder 250 race bike.   

[SteveD CB500F]

Or the five cylinder 125.

[heffay]

add another yea to your tally... although i've never ridden my 400 its still fun to look at.  besides, i think the 350 and 400 have far superior styling to the larger cb's.  it seems to me that the more cc's honda gave the bike... the less they thought about what the bike might look like.

 

[Bob Wessner]

The RC148, an interesting, 5 cylinder Honda model. If anyone is interested in the early days of Honda's racing, might want to see

http://www.vf750fd.com/Joep_Kortekaas/honda_race_history.html

Always found it facinating how Honda cranked out performance from such small displacement engines, particularly in light of today's 1-2 liter engines.

[supersport_CB400F]

The RC148, an interesting, 5 cylinder Honda model. If anyone is interested in the early days of Honda's racing, might want to see

http://www.vf750fd.com/Joep_Kortekaas/honda_race_history.html

Always found it facinating how Honda cranked out performance from such small displacement engines, particularly in light of today's 1-2 liter engines.

Bob, Mr Honda wanted some race wins so he made small bikes that would go around the IoM TT race course and win over the  Brit bikes that dominated, so the guys at Honda made bikes with small displacement’s and after a year or so won most things and sold your big 750’s on the back of it…..I’ve rode the course on my 400 almost #$%* my pants most of the way around going flat out…..how did MH get around that fast on his 250/6 he was a no fear guy for sure......what a man

[Zane]

.... I'm going to buy it.  ................ The tank has a flush fuel latch so must be 76........


Greg

You're welcome and good luck to you!

Do you mean flush fuel filler cap?  Because it was the '77 that was flush, if you mean the filler cap. 

The only way to tell for sure what year the frame is, is by the frame number.  Kevin Sullivan's great site "eagles call" will give you frame number reference.  That way you could determine whether you're being offered a 1975, a 1976, or a 1977 model with a 1977 tank.
 
http://www.dropbears.com/m/models/honda/cb400f.htm

[Uncle Ernie]

More fun than a barrel of monkeys, and good for a fairly lengthy ride, too.  The main thing I would suggest is to use Stable (stabile?) in the tank if you park it more than an hour without running it.

[Ted Nomura]

Yeah, I love my CB400F too, even though cam chain and rectifier can be a problem but then the cam chain problem was common with CB350 twins too and my Kawasaki KZ900 had a rectifier problem. I guess careful maintence and changing to electronic ignition is the answer. The only thing I like about newer bikes are that they are more reliable but none has the cool looks of the retrobikes, except maybe the new Triumphs. It seem like they finally got some smart guys there.