Every little bit helps!

worth checking that your fuel hose or any you intend to use as replacement in the near future is SAE J30 R7.

It need'nt be "Goodyear" just SAE J30 compliant
It is also the constant modifying of petrol that may cause problems with carburation, pinking and "going stale" the moisture from condensation at the bottom of the 30 yr old tank will also be drawn into the system and if allowed to dry out seems to form crysaline deposits in the carb and the bottom of the fuel pump-not good for a little used car.

With metal tank fitted cars (DS, GS, Ami) I've run half a litre of meths in (for a tank of petrol) to purge the water out of the system. I've found it works a treat.

I dont use tesco or any other uk supermarket petrol ,i have heard of problems too with water, dirt etc and poor running stories.

I was jetting a carb on a newly rebuilt 225cc motor in a lambretta a few years ago and i thought i'd try the then new 99 ron tesco fuel but it just would not run right at all until i filled up at a non supermarket garage. Some people get on fine with shite supermarket petrol but i've heard enough stories on top of that experience to actively avoid it in my van and on my bikes and they all get super unleaded from shell,esso etc.

What baron_matt says sounds interesting, i might treat my azu to some meths tomorrow

I often use supermarket fuel, and have never noticed any difference between that and petrol from name-brand garages. Indeed, the only time I've experienced any problem after filling up was on that fateful day when I inexplicably filled up with diesel!

i filled a tank up intentially with diesel on my outboard, well 50 50 diesel petrol, of course it used the petrol first, and was then running on diesel, plugs oiled up eventually and would only run on choke but it still ran on diesel!!!!

Likewise. Which, considering they all come from the same regional multi-brand depots, isn't much of a surprise.

We did have a problem with mucky fuel at the Swedish WM - but that wasn't a great surprise, since the little local filling station probably sold a year's worth of juice in five days, so would've been dredging the bottom of their tanks.

Yup ok for dragging the water through the system but if water laden fuel is allowed to sit in a carb and a fuel pump for a few months till it dries out it makes a mess.

perhaps its un filtered fuel lines where the water settles in the pump and with the fine steel dust that seems to be present in fuel it settles out at the bottom of the pump where it dries and forms deposits

Ill have a go at the pile of fuel pumps in the garage this week see if i ca find some horror pictures.

Does anyone know where the Tesco, Morrison, Sainsbury refineries are located in the UK?

Strangely, I believe they're generally located very close to the Shell, BP, Esso, Total, Texaco ones.

I also understand that the distribution depots are similarly tightly clustered.