Honda-SOHC

Hi everyone
Last year I finally bit the bullet and opened my 400/4 cases as I had the dreaded hairline crack in the bottom half. Got that welded.
As a “while I am there”, I also changed out the cam chain tensioner for the CNC version with bearing.
So now, starting to ride my CB again this spring, in the first time in 18 years of ownership, I have no more oil leaks and a properly tensioned Cam chain!

So much so, that I have to get used to the engine noise all over again. And I hate mechanical noises I cannot exactly identify...
I have a slight humming/whining noise that I think is the chain going over de guides. Do you recognise this change in sound after installing the upgraded tensioner? Bike runs good across the complete rev range.

For lack of another word...
My CB466f turned quite smokey recently. I determined that the head nuts (especially the 4 surrounding cil2, the one smoking) were not torqued down anymore. So either they came loose, or the head came down during break in, and I was too late re-torqueing them.

I replaced the head gasket yesterday and found something that I find strange:
I torqued all nuts in proper order to 20 Nm, next to 25 Nm, finally to 30 Nm.
Now, even after applying 30 Nm, I can still twist the nuts a little if I apply less than 30 Nm of force. You can see the nut AND the stud itself turn a little. They will come back to the original position however. Hence the “elasticity”: the stud twists a little.
This happens on pretty much all head nuts.

Is it normal?

I'm currently cleaning up my loom, just wondering about this.
The ignition switch of the 350f (under tank) has 4 wires.
Ignition off: no connections.
Ignition on: 2 pairs of 2 wires are connected.
Park: 1 pair of 2 wires is connected.

In the 'on' position, what is the functionality of the 'second' switching connection. Br - Br/w?
This circuit seems to just connect 2 positives of instrument lights and rear light...

Should I choose to do away with the "park" functionality, could I just go to a 2 wire ignition switch and hard-wire the br - br/w connection?

I'm a bit baffled.
I'm putting together a 350f.
While mounting the swing arm, I found the bolt (axle) to be way too long.. How?

I have a lot of CB400f parts laying around, as I parted 2 of them out in the last decade or so, but to my understanding, a CB400f doesn't even have an axle with grease nipples like this, let alone one so much longer.

Diameter (14mm) is spot on for the frame and swingarm by the way.

Any idea what bolt/axle I have here? CB500 potentially?

Lenght is 32,5 cm not counting both grease nipples.

Forum life: for better or worse right. I'm typing this as information and a 'warning' to other 350/400 owners:

As I mentioned in my other topic (http://www.sohc.co.uk/index.php/topic,21101.0.html), I did a frame-swap on my 350f.
Just a couple of evenings worth of tinkering, everything went smooth apart from getting the oil filter off, which required excessive force and destroying the oilfilter housing pipe-bolt. Luckily I had one in my pile of parts.

With almost everything back together, I thought it would be a good moment to finally take care of the small oil leak that my bike has had for the last years. There was always a drop, hanging from the oil drain plug. So I bought a new original drain plug seal, did the oil pump O-rings, new oil filter with O-rings, and gave everything a good clean, put oil back in..  Still a drop next day...  .

While researching in more detail, I spotted something that made my heart stop for a slight moment  ... A tiny hairline crack, just at the left front side of the engine, in the lower half of the block. Just behind the front left engine mount to be precise.

Well.. turns out I found the actual oil leak... Seems the bolt used in this engine mount, is slightly too long, and pushed the engine away from the mount, causing pressure in the aluminium and finally cracking the engine lower casing. Correct and too long bolt compared:
[ Guests cannot view attachments ]


Damnit! Thoughts like 'why didn't I feel this while tightening' and 'why didn't I check fitment before tightening' and 'why did I use that old bolt anyways' etc. But... that doesn't help, so I moved into problem solving mode. Like I said, the oil drip has been part of my CB since as long as I can remember having this 400 engine, so maybe it's good I finally find the cause.

With the bolt out (and pressure gone, the crack isn't visible anymore, not with the naked eye at least.
I wire brushed everything spotless, used a lot of degreaser and towels, went under with a good light source, put the bike nose-up high so the oil in the pan is in the back, and the leak stops.

As welding this is going to:
- require a full dismantle of the just assembled big-bore engine
- heat introduction may warp the casing.
- be a messy job, oil contaminated, old unknown alloy mix, no guarantee of actual solving it long term
- be costly as I certainly can't do that myself with my auto-mig spatter machine...
I made the choice to patch the leak with "Quiksteel 16402" epoxy aluminium. Seems to get extremely good results according to internet reviews, especially for events like this oil leak.

Job scheduled for this weekend...
Does anyone have advice or experience to share with regards to this sort of repair?

Will keep you updated.

Hi fellows,
looking for some advice. My 400-4 has a lot of clutch slip when the engine and oil are cold.
When warmed up, everything is fine.

I'm running Bel Rays 10w40 mineral oil, and the clutch isnt worn out.

In what direction should I be looking for a solution?

The fact that the slip disappears when all is warm, is just opposite of what I would expect...

----------------

Update on page 7!

----------------
I've introduced myself here:
http://www.sohc.co.uk/index.php/topic,11327.msg84751.html#msg84751

Will continue in this thread with my project updates.

----------------


Hey guys,

just wanted to show you my re-upholstered Giuliari seat. The guy who did this is a real artist (www.toniworks.nl).
My original seat cover was ripped, torn, etc. so needed to be re-done. The choice was to go for an original-as-possible new cover, but we had a one hour brainstorm and came up with a plan to give it a little custom twist (as my bike is also almost original, but with a twist).

I'm super excited with the result:










I'll make some better pictures with a decent camera later, but I couldn't wait 

Hey there,

I've been owner of this CB350f for a long time, right about 13 yrs). It was my first love after getting my license and I've never had any reason to part with her.
"Restauration" is coming close to the end now, so I'm researching a few things about tuning / setting up ignition and carburation.
Hope to find a lot of information here, and potentially sharing a few of my experiences.

This is her:


(I'm dropping the gold on the clutch cover)

I've done almost everything myself:
- Frame powdercoated (had it done obviously)
- All parts going on cleaned and checked for wear and tear, renewed when needed.
- Brakes refurbished
- Forks refurbished
- Hagon's at the rear, but those have been placed over 10 yrs ago already
- Wheels refurbished and painted black (rear 1.85 rim on the front hub)
- Heidenau K36 (3.50 front, 4.10 back)

- CB400f engine
- 4-2 exhaust with Dunstall Red-tip replica's
- Shortened fenders front and back
- Small tail light

- My Giuliari seat is getting a new bespoke cover. Original with a twist.

It's not a cafe-racer, it's not original, it doesn't go in any frame. It's just my CB to my specs.


At the moment, I'm waiting for a carb kit to arrive. Carbs are currently open on the work table.

Pleased to meet you, and looking forward to some more learning on these bikes