Topic: where to locate bronze swingarm bushings and jets for for cb400f?

[jessezm]

Hey folks, new here to the forums.  I'm back into bikes after a four-year hiatus, and have picked up a '77cb400f.  It's going to be a cafe racer, as it was too far gone for a full restoration.  I'm looking for a few parts, but can't seem to locate them.  Can you all suggest a good source for bronze swingarm bushings and larger sized jets for the carbs?  Also, do you know the right model/size K&N pod filters to fit these carbs?  I'm in the US (GA, to be exact).  Thanks!

[Bodi]

You can get bronze bushings from a few aftermarket catalogs. I've found them to be useless though, out of size spec as new. The other problem is with the collar, it wears out-of-round and will never fit properly in any bushing. This collar in not available new anywhere I can find. If your collar measure round at the bushing points, you can try the store-bought bushings.
Hondaman (on this board) offers a swingarm renovation providing bronze guides and regrinding (I think) of the collar, with the bushings machines to fit properly. This is the best solution.
The K&N pods that fit relatively well are the small short tapered ones, the diameter is whatever fits the carb throat (I can measure this but so can you...). You will have issues with carb jetting: if you're prepared for a lot of plug chops ,pulling carbs off, changing jets, reinstalling carbs, and repeating, then go ahead. You will probably need a pilot jet one size smaller and a main jet a size or three larger if you install a free flowing header as well. You will have occasional surging or hesitation is cross winds at speed but I think there's a performance improvement and the intake sound is pretty sweet. Supply of stock air filters is not good and there's no alternative element for the 400, like you can get a K&N element for the 750 stock airbox.

[jessezm]

Thanks much for the reply!  I'll have to do a search for Hondaman's mods, that does sound like the way to go.  I just took the swingarm off last night and haven't looked at the parts too closely yet, but the bike only had 5800 miles on it so hopefully the collar is intact. 

As far as the filters go, I am prepared for tinkering I'll have to do, given I really want the open look.  I'm using stock headers, also because of the look, but they are having to get re-chromed.  I know these are fairly restrictive but I'm really only doing city riding anyhow, and short trips on backroads, so performance isn't my main priority at this point.  Thanks for the headstart on re-jetting.

Other upgrades include dyna-s ignition and coils (green type--3 ohm) and aftermarket regulator/rectifier, but that's it for now.

Can anyone recommend particular clip-ons/clubmans and rearsets for this bike?  Thanks!  Any other comments are most welcome.  Once I get a camera I'll start a thread in the project forum

[Bodi]

Big trouble coming with 3 ohm coils and a Dyna S (you didn't specify Dyna model). The 400 has a barely adequate alternator that can not supply enough power for 3 ohm coils with points. The Dyna S uses a lot more power than points as well (the points are open about 1/3 of the time, the Dyna S only opens the coil power circuits for a few milliseconds each spark). An aftermarket regulator, regardless of the maker's claims, can not produce more electricity from the alternator.
If you have a stock 35w headlight you should get OK battery charging with a Dyna S and 5 ohm coils. Using 5 ohm coils and points is best, and if you want extended points life the same Hondaman guy sells an electronic box that buffers the points switching using power transistors to do the heavy work and reduces points current to almost nothing - the points eventually wear out mechanically but there's no arcing so they last years without adjustment.
You have no hope with 3 ohm coils and Dyna S, the battery will discharge steadily while riding. The Dyna S needs a decent voltage so it will start to crap out at low rpm as the battery gets discharged. Pulling the headlight fuse and keeping revs way up (if you can start it) will get you home but it's no fun (I've been there).

[jessezm]

Oh dear...

Well I was ordering based on the 400 four store's recommended parts on their catalog (they state the 3 ohm coils are recommended with the electronic ignition).  I've already ordered them off ebay, but maybe I can exchange them for the 5 ohm coils if he has them...  Do you think I'll be okay with the dyna-s and the 5-ohm coils?

[camelman]

I ran a 400F with a dynaS and the stock coils.  It ran fine, and never fouled the plugs.  I'm sure you'll be okay with the stock coils.

Camelman

[Bodi]

The 5 ohm coils will be OK. If you check dynaonline.com, they specify 5 ohm for the 350 and 400 fours because of the alternator output limits. At least they used to, their new site may not have a table that shows this.
The stock coils will be fine with the Dyna S too, as long as the HV cables are good. This is the weak spot on the old coils and the cables are integral with the coils: replacements cables can be spliced on using cable joiners though.
If you use Dyna coils it's best to get the Dyna wires in my opinion, but you can use any spark plug cable and use standard automotive distributor connectors on the coil posts.
You will have to slightly modify the coil support towers to attach Dyna coils, it's pretty obvious what has to be sawn off when you hold a new coil onto the towers.

[jessezm]

Cool, thanks everyone.  I think I'm in good shape now.  The Ebay guy I got the 3 ohm coils from is exchanging them with me for 5 ohms at no additional shipping.  Really stellar guy, I'm going to leave a great review in the review forum.  I ordered the dyna cables too so I should be set there.

Just sent my swingarm to Hondaman today, and Benjie is getting started this week on my tank and seat.   Still awaiting a bunch of parts but here's what's coming up"

--Polish hubs and rims, respoke, new bearings
--grind and sand the frame, powdercoat
--install tapered steering head bearings
--ship out pipes for ceramic coating (any thoughts on this?  it's either that or re-chrome)
--rebuild carbs
--rewire and relocate battery, install dyna-s ignition and coils and reg/rect.
--new controls (handlebars, switches, cables, lights)
--redwings shocks
--rebuild forks (they polished up great already!)
--stainless breaklines (caliper looks great polished, but thinking about ceramic coat--any thoughts?)
--Paint tank and seat

I've already cleaned, polished and painted the engine, and it looks sharp!