Honda-SOHC

Done and worth every penny. Thank you Steve for all the hard work.

A lathe is the best tool you never knew you needed until you get one Johnny.
Seriously go for it if you can and you have the space. You can get a good Myford ML7 with a single phase motor for not a lot of money these days. The one I would go for would be a Super 7 with a gearbox but they are expensive. I have a ML7, I paid £500 for it about 8 years ago and it came with a stand and a suds tray.
Once you get a lathe you will wonder why you never got one before!

Some excellent news to report regarding the shims  .

It appears I cannot count, or at least be trusted to write things down before I come indoors for dinner!
Long story short, when I was measuring the valve clearances and removing the shims to replace with the correct sizes and writing down the calcs in a notebook I tried swapping one from one valve to another to test the idea. It was the perfect size and in my success a) I was called indoors for dinner and b) I hadn’t written down what I had done. The result of this was the next day I went back out into the garage to continue and counted I only had 15 not 16 shims on the bench forgetting I had used one the evening before! This is why I though one was missing from the motor and I stripped the sump, cams and cam drive out trying to find a shim that wasn’t actually lost.....oh dear .
Anyway it gave me a chance to look deep inside the engine and find that sliver of metal in the strainer. But looking right through the motor there was absolutely no sign of any damage to the gears etc. All the dowels are where they should be as well (in the front cylinders anyway).  The metal shaving is too thin to be a dowel. I’m going to use my camera in the spark plug holes to check for any cylinder scoring but the motor wasn’t smoking when I ran it up for 40 minutes before the strip down.

I have cleaned the frame using Bilt Hamber alloy wheel cleaner and really pleased with the results. It got a five star review in tests and it really does work.

I have now prepared the front and rear discs ready for painting the carriers, what a boring job spending three hours with masking tape and a scalpel! I'll spray them with VHT when it warms up and cure them in the oven when the O/H goes to work.

It hasn't all been bike restoration I did undertake a domestic chore and cleaned the dishwasher whilst the wife went shopping. I cleaned the dishwasher first using the two stage process reccomended by Bryan. This involves putting a complete wiring loom in there first on a 65c wash. This was followed by using a dishwasher cleaner to do the real work and hey presto an immaculate dishwasher is the result

Welcome to the forum Roger and the encyclopedia of knowledge that exists on here.
Tim is 100% correct about the yellow bikes being the fastest. There is a rumour that Mr Honda himself blueprinted every yellow 400/4 motor after work when the factory was empty although as I said it is only a rumour....... allegedly........😳

The styling says it all, it was designed for European tastes with a cafe racer look, low handlebars and great handling (for its day).
I remember a road tester at the time saying the front header pipes have more curves than a page 3 girl (of course he wouldn't dare say that today)!
They make a fantastic noise when wound up as well.
I owned my first one in 1980. I've owned 5 of them and restored three of them from the ground up.
Get a yellow one and see what all the fuss was/is about 😀.
 

The noise of a CBX with a 6 into 6 would sound fantastic played through a hi-fi system 🙂.

Meanwhile whilst we await Murf's photos here's the sound of a CBX with 6 into 6 pipes. Turn the volume to 11 and enjoy......
https://youtu.be/UH4ZIsWy4SE?si=ZTZrzMlZof_WnpbN
It does sound a bit like a Laverda Jota👍