Tilley orange halo around mantle...

[Col_M]

means it needs a new vapouriser as it's running too rich right?

[dazcon]

Not totally sure, but it may be that the needle-valve is worn and allowing un-vapourised fuel to escape. I'd fit a new generator.

[Col_M]

That's pretty much what I thought, thanks for giving a second opinion

[Martyn]

means it needs a new vapouriser as it's running too rich right?

Yep. That's exactly the problem.

[Col_M]

Thanks Martyn, I had done a little research but just wanted some confirmation from people with experience

[Col_M]

Well I finally got around to getting a new vapouriser and it's burning perfectly now.

Once it warmed up I did a test run, I weighed it, 30 minutes later I weighed it again and it was exactly 30g lighter. So assuming the density of paraffin being 0.9g/cm3 then that's 66.666ml/h (recurring). The tilley tank is 1.5 pints, so near as dammit 850ml, taking the rate of fuel use that should give me 12.75 hours of run time on a full tank.
From what I've read that's quite respectable, I'm happy with that

[Toddy]

That's pretty good for such a good light really

I know that one gallon lasted us for a week of evenings during the powercuts in the 70's, and that was good clear light for a family of five to cook, eat, read, do homework , etc.,
By that reckoning you'd get a weekends evenings out of one fill up

cheers,
Toddy