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Hi

I've been asked by a friend to look at the wiring of his CB450. I'm an electrical engineer by trade but have done a complete rewire on a R80 Café Racer so I've learnt a little on bike electrics but its relatively new to me.

Looking for some advice on what needs to be done. The scope is make it reliable but nothing fancy. Bike is a CB450 1964 which I think is a K0 maybe?

Haven't got my hand on it yet but from what I've seen online.....

- There's no regulator on the early model. Any recommendations for a new rectifier with regulator built in? Presume these are reasonably standard item. Looks like a single phase alternator.
- He says it blew a main bulb. I'm putting this down to bad wiring or the regulator and high revs. Either way I'll make sure there's a regulator and run a new supply from a relay.
- What about the ignition system. K0 looks like 1 coil for 2 plugs. Does this mean both spark together so Cyl 1 sparks on Intake when Cyl 2 sparks on power?? Or am I being crazy. Also are there any good electronic kits for these? Is there any point or is a properly adjusted points system just as good?

Everything else looks simple enough probably makes sense to put in LED lights. Any other advice would be welcome.

Forgot to mention based in Ireland as well.
 

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Welcome - don't think the K0 goes back to '64, pretty sure it began in '65 though the build date on the frame tag might be late '64 I suppose. Modern rectifier/regulator combos are available to get the most from the charging system. The jury is still out on a good, long-term reliable EI for Honda twins, but the old reliable points still works very well. Unless the bike is one of the rare 360° crankshafts (opposed to the more common 180°), it should have 2 coils, one for each plug.

I realize you're working on this for a friend, so a Member Introduction might not apply to you personally... but here is the link to some reading related to that and other things about the site

https://www.hondatwins.net/forums/23-member-introductions/121120-critical-read-before-posting.html
 

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1964 k0 wiring?
Just reading this thread.........
Interested to note the reference to the 360 degree early bombers and the single coil.
I think it would be helpful to provide the engine number of the machine you intend working on to confirm it is the normal 180 degree engine and not by any remote chance the earlier rare 360 engine.
I am presently restoring a very early 360 degree engine bomber. The engine is rebuilt but have not got as far as connecting the wiring.
The very early workshop manual suggests it is a twin coil but I wonder if it should be a single coil.
Is it a single coil on the bike you are looking at working on?
 
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