1967 CB450K0 Black Bomber Rebuild - By Royhall

[royhall]

Success, nearly.

After 7 weeks of waiting the Bombers V5C has finally arrived. All the details are correct including the engine number change but unfortunately they forgot to make it "Historic Vehicle". So a little trip to the post office and it's now taxed and the V5C is on it's way back to DVLA. After all you cant expect the DVLA to get it completely right first go.

I will check online tomorrow to see if it's tax status has changed, if so I can finally get on with the setup work. I registered my 750F2 for Historic status at the post office on 1st April and am still waiting for that V5C to return.

Can the vehicle be used before the V5 returns as the MOT status online is showing as unknown.

[Nurse Julie]

Yes, it can be used immediately Roy, as long as its insured of course. Did they give you the receipt for £zero paid?

[royhall]

Yes they did, stapled to a declaration of MOT exemption. It's been insured under my classic policy all through the restoration.
It appears from the paperwork that when dealing with the DVLA you must never ever use the words rebuilt or rebuilding. Your safe with repaired or restored, but to DVLA rebuilt means something completely different and will cause you a world of pain.

[Nurse Julie]

Yes they did, stapled to a declaration of MOT exemption. It's been insured under my classic policy all through the restoration.
It appears from the paperwork that when dealing with the DVLA you must never ever use the words rebuilt or rebuilding. Your safe with repaired or restored, but to DVLA rebuilt means something completely different and will cause you a world of pain.

😂😂😂😂😂😂

[Bryanj]

To the non engineers at swansea rebuilt=ringer

[AshimotoK0]

Great stuff Roy ! You are on the road with it at last.

What's you advice on mine? I have the V5C in my name (from a 1967 frame I had) but it states the original engine number. The cases I have for it are fairly close to the original and luckily, for some reason, all  UK bombers have their engine ad frame numbers miles apart, so the cases are definitely 'age related'. When I make the V5C change for the replacement engine ..... do I act like I have swapped all of the engine parts over from the original as you described or just state that the engine has been  replaced and get a 'sales receipt' for it?
There was a time when you just made a simple change of engine number but I guess from recent experiences and yours that the the DVLA have become more snaggy recently on engine changes.

[royhall]

The big issue is what happened to the bike that the doner cases came from. If it was correctly scrapped or just fell off the radar then fine, but the bike may have been stolen and split for parts. If that's the case then it could be a problem.

I wasn't originally going to change the engine number until I got a V5C, but due to the original having the number missing and me suspecting that it wasn't the original engine I thought I would come clean and change it now. My original may have been taken and already used in another bike causing the DVLA computer to flag up a problem. Does that make sense.

I would go with the replacement engine receipt if one is available. But wait until the bike is built as it may cause an inspection request. It's a bloody minefield these days, mainly due to the huge number of vehicles being stolen and ringed or split for parts (thank eBay for that).

[AshimotoK0]

Good advice Roy ... All of my CB450 Bomber stuff  came from the same source and I suspect had been owned by the PO for well over 30 years untouched and probably off the DVLA radar now (but you never know). I do have two, additional,  spare UK frames as well as my own bike one that could well match the several sets of spare crankcases I have but unfortunately I have no paperwork for them. Julie recently and kindly  put me onto a guy on  FB who runs a service where you give a frame number and they check for a registration  (you pay a fiver if they identify it, nothing if they don't). I bounced my two spare frame no's off him but both came back as unidentified.

[royhall]

Just for the sake of completeness. I had a charging issue with the bike that was covered in another thread.  http://www.sohc.co.uk/index.php/topic,25561.0.html. The bike is now complete and legal for the road. Just in time for summer if it ever happens. And with perfect timing my V5C has just dropped through the door with the change to 'Historic Vehicle'. When I get chance I will do a little video of the bike running.

[royhall]

Just a little update. The Bomber hasn't seen much use since it was completed. This is mainly due to it running rich and fouling the plugs with sooty black deposits. Strangely though it runs very well. Just changed the oil as it's been in a while and it smells badly of petrol and poured out like water. Probably unburnt fuel washing the bores and getting past the rings. As you may know from earlier in the thread I am running 500T carbs with 450 jets and needles. These carbs don't have adjustable needle positions or I would have dropped the needles a notch or two. Not sure what to do here, maybe a Mikuni conversion kit, anyone know anything about that. Obviously I can't use it with oil contamination like that. Don't seem to be having much luck with carbs lately.

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[Oddjob]

496

[royhall]

There's not too much available for these carbs by way of jets and needles. The float heights are a bit lower at 19mm already. They should be 20mm as stock. Looking through Google this appears to be a very common issue, to the point that several companies sell a complete Mikuni conversion kit. These kits come with everything required but at an outlay of about £460.

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[Oddjob]

497

[royhall]

You may be correct there. Problem is that over the 2 years since it was finished I have tried all sorts to lean it out a bit. Any changes just make it run badly. I get the impression from the internet that these CV's are just rubbish carbs. They were probably okay new but 50 years of wear hasn't helped.

[McCabe-Thiele (Ted)]

I would have thought the lower the float height, lower fuel level in the bowl. the lower the corresponding fuel pressure to the main jet so the leaner the mixture.

PS I'm dark haired.