Ged, thanks for that is been a huge help. I'm going out tomorrow to buy some fresh paraffin as mine is knocking on now.
There is a built in pricier needle that can be seen when the valve is fully opened. I'm not entirely sure that its building enough pressure as when I open the relief valve the hiss is almost inaudible.
Your paraffin is almost certainly fine, it doesn't go 'off' really. It does sometimes get moisure in it but that sinks to the bottom and you can get rid of it easily. If you put a little bit of IPA in the fuel it will take up small amounts of moisture and exhaust it through the burner. Some equipment might have mild steel parts e.g. fuel tanks and it can be a good idea to do that routinely to prevent corrosion, but if it's stainless it isn't so much of a worry. Th most important thing is to make sure the fuel is clean. The small jets are easilt blocked by tiny bits of debris. Give the tank a good wash out with clean fuel if it's got bits of crud in it.
When the tank is up to pressure I would expect a very audible hiss on letting it down but you might just have a quiet one.
There are three or four places where it might leak but it's mostly fairly agricultural so it should be easy to fix. One likely issue with these old stoves is hardened seals. They're mostly pretty easy to make, but the non-return valve seal is tiny so that might be a challenge. You might be able to get a new one from e.g. Base Camp, but I had a quick look just now and I couldn't see spares for these stoves listed. Best send them an email. I gather that the original manufacturer hasn't been very forthcoming with spares in the past but things might have changed. Don't do anything you're not completely comfortable with, you can easily damage fiddly little parts and you want the seals to work when you've finished.
One way to find leaks is to pump it up, put it in a bath of water and look for bubbles. Obviously not when it's hot.
It won't be damaged. Can't necessarily say the same for the bath. You might want to make sure there's no water in the pump body afterwards.
If you don't fancy that then get some soapy water in a squeezy bottle and squirt it around, see if you can find any bubbles that way.
Another way is to see if the stove burns OK. It should give you quite an impressive roar and it shouldn't need extra pumps more than about every quarter to half an hour. It will need extra top-up pumps more frequently if that's the right word when the tank is nearly full of fuel because you get more pressure with less air when it's full.
You could take it to someone who's familiar with it, there are quite a few people around who know and love these stoves.
, the No2 is a different beast so leave the 12 as it is and run paraffin and if you have nowt else diesel, ignore posts saying it might or could its just not worth messing around with petrol/naptha...you want to burn that buy a stove designed for it, get a Coleman et al.
