Diesel bike build in GB still viable?

[Brainsparks30]

All this crap about emissions and tax is giving me a headache. I am going to do a build anyway (eventually) probably with yanclone engine, and I do have an old Yawa outside on its last rebore...

So the question is, if I build a bike from scratch, will it be a nightmare to put on the road?
Is it a better idea to just do an engine swap into existing frame and not mention it?
I heard stories about using the steering down tube and the vin plate from a junker, and 'build around' it as such so it remains a classic.
Maybe a...GASP, hybrid? (mountains of lithium )

If it all goes the way I think it will, we will all be a cottage industry repairing junk to keep it running. Or we all clear off to somewhere not insane that still loves innovation.

But clearly, I want to know. So if anyone has some idea, please tell.

[gilburton]

Best to get a complete bike/frame with v5.
Once built all you have to do is register the engine change to "heavy oil" and the engine number change and send off the v5 with the changes.
What will happen then is they will send you a letter asking that a qualified engineer inspects the bike.
This is NOT a full engineering check of the bike it's just to verify the engine number matches what you say it is.
My local friendly MOT man checked it for me and gave me a statement on headed paper which I sent off. Job done the v5 came through in a couple of weeks.
You could get it checked before it is ready for the road so that by the time the v5 comes through it will be finished.
I would assume if you keep all the receipts for the bike and engine and sent them off, along with the engineers inspection confirmation(or even an MOT)
when you apply, it will all go through.
UK bikes don't have emissions checks so it shouldn't be a problem especially if using an existing registered bike..
Biggest problem is insurance so a post on here when you are ready might get some companies to approach. The insurance mind can't get it round their heads that you have REDUCED the power output to 125 level when you fitted a 400cc engine so online insurance applications don't work you need to phone up specialised brokers usually.
There are not many DVLA inspection centres left so if you scratch build a frame the bike will need a proper inspection which might involve a few trips to get it past the regs and obtain a v5.

[alexanderfoti]

Yes I agree, that is the best way to do it.

I recently renewed insurance with footman james. Competitive and where happy with the engine mods.