1975 CB400F "un-cafe"

[kartin]

Back from UK trip with a suitcase full of goodies! The above mentioned exhaust looks pretty good so I might re-visit whether to paint black or not. I think I now have most of the clips/brackets/grommets that were missing. Also got some correct handlebar switches as well as an ignition switch. The handlebar switches check out fine on the meter but the ignition switch didn't show any continuity and wouldn't even turn to the park position. It has clearly been opened before but not cured. I found two issues inside:
- one of the springs that press the little "bridging" pieces onto the contacts was not in place. Maybe this was meaning it didn't sit properly and was preventing the switch from turning properly? Just a guess...
- the strips that form the connector spades are attached to the actual switch contacts by a sort of rivet affair. I found continuity to the rivet head but not on into the strip. I cleaned the rim of the rivet and adjacent strip with a dremel wire brush and bridged the two with solder (being quick so as not to melt the plastic holder). I only did the 3 that are easily accessible - the other 2 seem fine.

The combination of those 2 things resulted in correct operation and continuity in both key positions. In my haste to try it I forgot to take pictures of the solder fix but they are on the back side of the piece in the top-right of the picture with the fabric background (not my picture - just one I found). The other switch picture shows what I believe is the correct orientation of that piece into the housing to get the correct connections for each switch position (TBV when finally fitted to the bike). Continuity testing is made a bit confusing by the fact that there are 2 brown wire locations which are not connected when the switch is stand-alone but are connected in the loom, so you need to try both.

A huge "thank you" to people who have posted colour-coded wiring diagrams, including what wires should be connected in each switch position - they are invaluable for this sort of testing.

[kartin]

Continuing to clean up the various bits. The hardest work so far has been the front brake components. I thought I would give the OEM originals I picked up a try before resorting to reproduction items but they have put up a good fight! Even the pads were well seized into the caliper halves, never mind the piston itself... So, freeze, heat, penetrating fluid, tap-tap-tap with a hammer and keep repeating the cycle, trying to break the corroded joints... Eventually the master cylinder piston yielded with some heavy blows via a drift in the banjo end. The bore looks surprisingly good so we'll see what happens there. On the caliper end of things I had to get really brutal to get the old pads out, basically drilling and chiseling until they came free. As for the piston, I thought I was being clever by drilling and tapping a hole in the face then using a bolt + washers to pull it out but all that did was pull the face out of the piston! I tried hammering the sides of the piston in to try and collapse it, to no avail. Eventually I did the drill+tap thing again, this time with the bolt bearing on the inside face of the caliper and out it came! You can see the big pile of grease on it from the attempted grease gun method (which failed). The sealing face is on the piston (which will be new, obviously) and the groove in the caliper (which looks good) so again, worth a try. I'm lucky in that I live in a neighbourhood with 25mph limit and only one entrance/exit to "regular" streets so I can test extensively in a benign environment. If the brake doesn't behave flawlessly, I will ditch it in favour of new parts before I venture out onto "real" roads.

[McCabe-Thiele (Ted)]

Yikes that caliper piston removal sure was a swine -10/10 for persistence.👍👍👍

[Johnny4428]

Good work there. That brake hasn’t functioned for a considerable time.

[Matt_Harrington]

Good job it wasn't a twin post caliper. I'm not sure you would have succeeded! Good effort...

[taysidedragon]

I would have given up on that caliper. Well done for persisting. 😲

[kartin]

Continuing to clean/paint/refurbish/fit parts. Nothing much out of the ordinary worth reporting except for 2 points that might help others:
1) The new bronze swingarm bushes I had bought seemed VERY tight in the swingarm, even when frozen. I double-checked that the insides of the swingarm itself were clean and not marred from the removal of the old bushes - all good. I didn't want to risk getting stuck half-way so I chose to shrink them ever so slightly with some wet-n-dry while spinning them in the lathe - see pic. Then with freezing and grease they went in beautifully using the threaded rod method.
2) I had read that I should fit the rear brake pivot assembly before fitting the swingarm but I would add to that to fit the pull-rod to it as well, especially if you want to insert the clevis pin from inside to outside so you have access to the hole end. I tried to do it with the assembly in place and it was a fiddle.

[kartin]

Back from another trip to the UK with a couple more parts:
- a CB250N Superdream (aftermarket) headlight: A mod some people use to enable using a 60/55W H4 bulb. I don't even have a CB400F bucket so I'm using the whole thing for now. This meant relieving the bucket a bit to clear the ignition switch and indicator bar.
- LPM sidepanels (I know they ship to the US but since I was going to the  UK and they're not hard to transport...). The material looks nice and meaty so hopefully they'll prove to be robust.

Also, on my Yoshi exhaust, I made a decision which I may regret... Despite looking in quite good shape in the overview pics, the insides of the first bends as the pipes leave the engine are quite rusty. As a bit of an experiment, I used some high temp primer and silver paint just on that first section. The idea was to stop them rusting further and for the colour not to be too obvious. The pictures really highlight the transition so we'll see how it looks once everything's together. In hindsight I should have just done the inside of the bend (fairly hidden). If worst comes to worst, I'll go full matt black which is how my original bike was anyway.

[Oddjob]

Whereabouts in the UK are you visiting and is it for family or business reasons, I’m thinking why not bring parts over to the UK that are scarce over here and post the on to members who ask, make a little money to finance the bike restoration. Nothing heavy of course, just small parts that fit in your carry on.

Oh and maybe consider chrome ceramic coating for the header pipes

[kartin]

We fly into Manchester to stay with relatives near there, but also often drive down south to visit other relatives. Do you have particular parts in mind? Going towards UK is usually our lighter luggage direction so it could work. I don't even particularly want to make a profit if it helps people get what they need, as long as we can work out how the parts get paid for.

[Oddjob]

Just an idea but lets say points and condensers for the 400/500/550/750. They all use the same ones IIR and they tend to be cheaper in the States so maybe buy a few yourself or if that doesn't work let me know and I'll buy them and you bring them. They are small, light and easily transported in hand luggage. Must be original Honda ones though, the cheap ones don't work as well.

I actually live near Manchester in Stockport.

[kartin]

Ah, sorry! For some reason when you said "parts" my brain went to "used parts". If we're talking new OEM, these are the two places I've used so far:

https://www.ronayers.com/oemparts/c/honda_motorcycle_1977/parts
https://www.southsoundhonda.com/--xpartsstream#

South Sound prices are slightly better but Ron Ayers website seems to be more accurate about what's really available. For example, I tried to order a valve cover gasket from South Sound. It let me order it and seemed to say it was available but I got an email back saying that was not the case. Sure enough, Ron Ayers don't show it as available. Anyway, have a fish around and see if anything that's available seems worthwhile.

[taysidedragon]

Good kickstart levers for 400f or 350f are always in demand. Check for cracks in the knuckle.