Topic: '75 CB400F time line and pictures

[tsflstb]

It’s been a slow day, so I flipped through some old pictures.  I don’t think I’d have done nearly as much work to this bike if it weren’t for this place.  I lurk here a lot more than I post and always learn something.  Anyway, I always thought the 400cc class of bikes was really neat.  I was looking for the CB1 model, but stumbled on this one just a few minutes after the ad hit Cycle Trader.  Racing machinery always looks right to me.  I like it when everything you see serves a purpose - to make it stop, go, or turn.  I didn't really shoot for the classic cafe look.  My goal was to just make it as minimal as possible - like a race bike but legal for the street. 

This is the bike as I bought it:


I got it cheap because it wouldn’t go into 1st gear…looking back it was probably an issue with the shift mechanism.  I was gung ho and immediately tore into the engine to replace the transmission with a better looking set of gears, dogs, etc from ebay.  More on this later.

I knew I wanted a solo seat so again to ebay.  I liked the lines of this one, but it just never looked right.  Figured I’d use it until I found something better.  Also ran drag bars for a while.


Went on a quest to see how quick I could get this thing to steer.  Added shocks 2” longer than stock and dropped the forks about an inch in the trees (had clip ons at this point).  Also found a Kerker pipe on craigslist and mated it to a little Supertrapp baffle.  Eventually came to my senses and put the forks back.


I bought a poorly manufactured oil seal kit for the first transmission replacement.  It didn’t have the proper sized orifice to let oil into the output shaft.  I didn’t notice it at the time.  The transmission was getting a tiny drop of oil instead of the steady stream it needed.  It lasted a few hundred miles before it seized up solid at a little over 60 mph.  I was lucky nothing worse happened.


So there was another rebuild with OEM Honda seals.


After running it for several months I have a bit more confidence and started to spend more time on it.

Rebuilt forks, new wheels, gauges, triple tree, drilled brake, etc.  Also found a smaller seat.



As it sits today:


I’m working on some rearset brackets right now.  Also waiting on a steering damper to arrive.  I’m going to add a Dyna S to hopefully get my electronic tach a better signal along with the other benefits.  I have an extra tank I should get around to painting too.  Thanks for all the help around here.

[CharlieT]

That's a sweet looking 400. Like the black/red thing, especially the black rims. Nice 4-1 pipe on it. Bike looks very......umn, purposeful

[trav72]

Looks great!  I've been looking for those shocks.  I think I may have a line on them.  Those wheels look great as well!  It's exactly what I've been looking for.  Where did you get them and what size did you get? 

[stay youth]

I have always loved your bike. I have secretly been plotting and trying to turn mine into one similar to yours. What kind of dampener are you getting? Where did the those rims come from?


More pictures!

[mattcb350f]

I bought a poorly manufactured oil seal kit for the first transmission replacement.  It didn’t have the proper sized orifice to let oil into the output shaft.  I didn’t notice it at the time.  The transmission was getting a tiny drop of oil instead of the steady stream it needed.  It lasted a few hundred miles before it seized up solid at a little over 60 mph.  I was lucky nothing worse happened.

Who manufactured the oil seal kit, for the benifit of the rest of us...

I seized a 400 Husky on the road at WOT. Not fun at all but never laid it down.

 Matt.

[amemoryoncelost]

 Yes more info on the seal kit and the rims as well. Love the look of excel rims since they were the rims to have growing up on dirt bikes, the black rims looks soooo nice and the rims on my 400 are pretty grimey and been pondering my options!

 Bike is so good, an inspiration to any 400f owner or any sohc owner with a project to start on!

[DarkRider]

Bike looks great man.

Any chance you still have that first solo seat you used?

[tsflstb]

Who manufactured the oil seal kit, for the benifit of the rest of us...

I think it was TK or TR or something.  One of those knock-off type brands.  The Honda seals are still available.

Here's a topic on the lock-up from a while back.
http://forums.sohc4.net/index.php?topic=11259.0

And the rim saga is here:
http://forums.sohc4.net/index.php?topic=29889.0

Oh and I sold the bigger seat a while back.

[bzr]

Bike looks amazing! Where did you get the seat?

Love the rims, I'm planning to do something similar.

[tsflstb]

The seat is from clubmanracing.com.  It's the short, wideline Manx seat - made for a Norton but fits the 400 pretty well.

Working on the steering damper installation now.  I bought a mount that's supposed to be made for the 400F from ebay.  Also got a 3-way adjustable damper that was used on an old CBR racebike.

It's situated so when the front wheel is straight ahead the damper is in the middle of it's stroke.  The problem I've run into is that it's slightly too long and the rod hits the engine when it's mounted where I initially wanted it. 

I'll add a spacer on the lower triple tree to lower that end and have moved the frame mount down some.  This way the damper rod just barely clears the exhaust when the front wheel is all the way to the right.





Needs a little touch paint now after wiggling the mount against the frame.

The big question is:  Do you think the exhaust heat will hurt the damper in this position?  Ideally I'd like it farther away but this is the best place to get it at the right angle to function.  I can see it getting pretty warm in traffic though.  Most dampers I've seen on these older bikes are installed pretty close to these old air cooled engines?  Anybody had problems?



I'd rather use the hole that's already there, but the other option is to use one of those clamps that goes on the fork tube.  The damper works fine now and doesn't bind up at all, so if the heat isn't an issue I'll probably just leave it.

[tsflstb]

Here is the finished steering damper.  I found a short piece of round brass rod rolling around in an elevator at work.  The elevator seemed to function without it, so in my pocket it went.  With a little hacksaw and polish time it works perfectly as a spacer to get that damper at the right angle.  Still need to touch up my frame downtube and shorten the mounting bolt a few threads, but I'll wait until I pull the exhaust again to pretty everything up.



I also got a Dyna S installed - no pictures of that but trust me it's under the points cover.  They make a handy little adapter so that my electronic tach functions as it should.

Next steps are to buddy up with someone who can MIG or TiG weld and get some mounting plates on the frame for my rearsets.  I'm also waitng on some Koni shocks to arrive and will see if I like them better than what I have now.

[stay youth]

Looks great. How hard was it too install the dyna kit? I need to upgrade my points. What kind of springs  do you have on the front end?

I'm working on a "giuliari" style seat for my 400f currently

[tsflstb]

The Dyna went in pretty easy.  I didn't have a timing light handy, so I just set it statically.  I ran some alligator clips to my tail light to set it at the regular and advanced position.

I just have the stock front springs with some preload cranked in from the TTR400 adjustable fork caps.  With 15W fork oil it's balanced pretty well with the longer, stiffer shocks.

Good luck with your seat.  I always wished there was a Guillari seat made for the 400.  It should look at home on your bike.