Topic: My 77 CB400F

[rluser]

It has taken a bit, but as suggested when I joined I am starting a thread for the bike that brought me here.  This is how she looked when I received her.

[rluser]

An oil check, tank rinse, fresh fuel, charged battery, and warm day got her running.  That revealed a suboptimal state of tune, slipping clutch (it was frozen up when I first saw her), and leaking forks.  The seat and tank are only held on by gravity.   After about 250 miles I pulled the previous owner's plugs.

[rluser]

A plug swap followed and 250 miles in a day.  This ishow the new plugs looked.

[rluser]

I rode across the county to get my timing light, but it wandered off, so I had to find another.  That was not entirely a success because the idle is rather unstable when fully warmed and I did not recognise how to move the 2-3 timing relative to the 1-4 timing.  While the bike was on the stand for timing operations fuel started running out the #4 pod.

Now that I have looked at the right cover parts diagram again, I shall have another go at timing before pulling the carbs.
The oil went from "used" to "nasty" so yesterday she got a change.  The 77 seems to lack the oil filter bolt collar that earlier models had.
It seems I did not get that surface clean, because after warmup and a 15 minute ride, she left a drop of oil from the filter cover when parked.

[rluser]

I bought her to ride, so I have no firm plans about where she is headed as a project.  For now the main focus is to make her more ridable.  Better state of tune, front suspension, solid attachment of rider, tank, and seat to bike, some sort of turn signals.

Oh.. and it turns out that while the bars do not contact the tank, the headlight brackets do

[Mark1976]

  that's a project....
 You'll need to get and or download a service manual, that'll get you started in the right direction. It'll show you how to set the points, adj the timing, the valves and adj the cam chain, check the float height (look up clear tube method) and adj the idle mixture and sync the carbs, then you can set the idle. If its still idling rough, then you can look for vaccum leaks, check the intake spigot o-rings and carb clamps. Also, Its got those pod air filters, so your gonna have to pull the carb rack eventually either way and find out what kind of jetting you've got there. Once you've reached that point you may as well tear the whole rack down and clean the internals and replace what ever o-rings need replacing. You more than likely have dirt and contamination in there as well. Good times ahead.... ask questions as you go. If its a '77, you've got a 75-76 gas tank. Can't believe you rode 250 miles on those tires. You gotta be a youngster....

[rluser]

If its a '77, you've got a 75-76 gas tank. Can't believe you rode 250 miles on those tires.

The frame is 77. 

250 miles twice!  I am no fan of  Firestones.

[Mark1976]

   So anything I say from this point forward is just my opinion, what you choose to do is up to you, your bike your build no judgments.
   Your missing many items I consider essential to having a functional daily driver, looks like you'll need a tach, a couple of functional fenders, the front fender will help to stiffen up an already flexible front fork. Side covers really help to make this bike a bit more attractive, and to be honest if you want a responsive rideable bike you may want to consider reinstalling the oem airbox. Its just easier to maintain and troubleshoot and it'll give you a more predictable responsive bike. That and it'll make the ride a whole bunch less noisy,  with pods you get a lot of intake noise. The tank hold down strap is available, and your going to have to fab up a seat hinge arrangement, that or go ebay and buy a original seat. Just my 2 cents. 

[Stev-o]

Definitely a project and Mark touches on some important points.

[rickmoore24]

Cool project! Not sure if this was an issue on the '77 frames but you may want to poke around (literally) at the bottom frame rails. Particularly around the side stand area. I know the '75 frames are notorious for letting water into the frame tubes and rusting out, from the inside out. My 400F was so bad I hade to source a replacement frame. Good luck! Rick.

[rluser]

... items I consider essential to having a functional daily driver, looks like you'll need a tach, a couple of functional fenders, the front fender will help to stiffen up an already flexible front fork. Side covers really help to make this bike a bit more attractive, and to be honest if you want a responsive rideable bike you may want to consider reinstalling the oem airbox. Its just easier to maintain and troubleshoot and it'll give you a more predictable responsive bike. That and it'll make the ride a whole bunch less noisy,  with pods you get a lot of intake noise.   

My pictures do not show it, but it is actually the speedo missing.   The first thing mentioned to me (by RAFster122s) here about this bike was the loss of front end stiffness due to the missing fender.  Until then that had not occurred to me.  At a minimum I'll put an arch in there.  I spotted a modern front end on craigslist, but it turned out to be a Kawasaki 125 which seemed more trouble than it was worth.  It happens the airbox itself is still in this bike.  The lid, element retainer, front and rear ductwork, and some of the PCV system are missing.    There was a time the noise would have bothered me, but that time has passed.

Cool project! Not sure if this was an issue on the '77 frames but you may want to poke around (literally) at the bottom frame rails. Particularly around the side stand area. I know the '75 frames are notorious for letting water into the frame tubes and rusting out, from the inside out. My 400F was so bad I hade to source a replacement frame. Good luck! Rick.

Thanks for that tidbit.  I had about 20 miles to go just after reading this, so I rolled around on the ground with some picks.  Seems OK.  Does the water enter from the rear?

[newday777]

There is usually a vent hole near the V in the frame where moisture and dripping rain water can roll inside the side tubes and down in near the kickstand, probably when the bike is left on the side stand in the rain without a good cover (or possibly if riden in lots of hard rain??)
This is a 750 frame I just picked up that has the vent hole. I've had gl1100 frames with rusted lower frames that have an open hole where the removable frame member gets bolted to the frame, the rain water rolls down the frame into the open holes in that section.
Honda never put any rust protection inside the frame members. The goldwing forums suggested oil in the holes and swish around or fogging oil will help slow any rusting down.

[rluser]

Hey, SOHC4heads,

I had not progressed much on this bike other than some tune-up stuff.  Last night someone stole it (and a lawnmower) from my GF's garage in Canton, Ohio.  The frame is tagged CB400F2102422

[rickmoore24]

Oh man, that fricken sucks. I hope you find the bike and lawnmower, and the scumbag gets caught too. SMH....

[newday777]

Noo!