My Coleman® Camping Stove
Coleman Dual Fuel Stove No.533
 On the whole my Coleman® petrol burning stove does a very good job, and in the most part is reliable. It runs on Coleman® Fuel or unleaded petrol, which the later is readily available in most areas and is relatively cheap.
 When in use the stove boils water very quickly indeed (10,500 BTU's). But is less good when it comes to cooking food that requires anything other than 'full throttle' such as frying sausages or bacon. Most campers I know like nothing more than a really good fry-up, including me. It is true to say you can turn the heat down. However after a little time the flame begins to burn rich. Turning from a blue/green colour to yellow, leaving a deposit of soot on the base of the pan. Maybe incorporating some sort of adjustable diffuser would be a better way to control the amount of heat delivered to the pan, rather than restricting the flow of the fuel - a project for later perhaps.
 Having paid quite a sum on the initial purchase of the stove, one would hope to slowly recover some finance from using 'cheap' fuel. When compared with the alternatives, such as calor gas or methylated spirits.
 However, I have now got my second blocked 'generator'. Not bad you might say as I've now had my stove for twelve years and use it regularly. But I've had a 'Camping Gaz' stove for well over thirty years and all I've replaced is the disposable gas cylinders. So it doesn't compare well. But for some reason, beyond me, I continue to be fascinated by petrol/paraffin burning stoves. Bizarre really.
 The generator is what they call the brass tube that runs across the top of the stove, in the flame. It infact carry's the pressurised fuel from the fuel tank to the burner. As the fuel passes along the tube and through the flame it is heated and vaporised. It does not burn inside the tube as there is no oxygen present. The vapour is released underneath the burner, then travels up through the burner rings before being ignited.
 Here is a close-up of one end of the generator, the 'L' shaped piece of brass clips into a hole in the on/off valve assembly. As the stove is turned from the 'off' to the 'on' position, it moves the stainless-steel wire about 1/4" along the smaller micro-bore brass tube which is within the the larger brass tube you can see here. This appears to have the effect of keeping the jet at the other end of the generator clear of carbon deposits.
 The micro-bore tube can be seen here with the stainless-steel wire entering it.
 And at the other end, the removable jet. I guess you could have several of these in different sizes for using different fuels ;) although the newer generators seem to have a nonremovable, one piece assembly. Which also makes cleaning all the more difficult.
 With the jet removed, the stainless-steel wire can be seen protruding from the micro-bore, which is located in the centre of the outer tube. Aligning it with the jet. When I removed the jet there was a black tar like residue ddeposit in this area, as can be seen below the threads. Perhaps a yearly strip and clean in the way of maintenance is the the way to go.
 A cleaned jet and the stainless-steel wire
 In between the two brass tubes is, what can best be described as a spring. A spiral of solid wire running from end to end. Not dissimilar to a bending spring. As I suspect that these units are made from straight tubing, and the last part of the manufacturing process is to bend them into the desired shape. This would help to prevent the tubes kinking as well as keeping the the micro-bore in the centre of the outer tube. While in use, it forces the fuel to spiral, increasing the distance travelled, covering a greater surface area, therefore helping to vaporise it and making the generator more efficient.


 
Coleman 533-700 parts list
 Spare parts list for the 533-700 duel fuel stove
  1. 220C1401 Filler cap
  2. 220A6201 Pump repair kit
  3. 533-5891 Unleaded Generator [442-5891] same
  4. 508A5571 Valve assembly
  5. 400-3451 Burner ring set
  6. 425A3451 Burner assembly
  7. 400-5401 Grate assembly
  8. 533-6151 Fount
  9. 639-1091 Pump cup and clip
  10. 400-5261 Burner box assembly
  11. 400A1261 Generator bracket
  12. 400-0601 Screws, 6 per pack
  13. 200-6381 Check valve and air stem
  14. 530A5071 Pump clip
  15. 508-7631 Carry case

 
   
 I've had a reply to an e-mail I sent to Coleman. But it's not much help unfortunately. An extract "...You really can not clean a generator. Even with soaking it in denatured alcohol, they don't come clean. You should just replace it" well I might have to do that, but I'm going to try a few things before that.
First, heat was suggested by a friend. This could be a goer, I remember my dad heating up his motorcycle exhaust with a blow lamp or oxyacetylene to clear the carbon blocking the flow of gases.
First I tried placing it on a domestic gas cooker ring. This successfully heated the generator to a red glow, but no difference in the flow of fuel was achieved. Next I tried a gas blow lamp, this time the generator was glowing a brighter red. Unfortunately I went a little too far with this method and burnt some small holes in the brass tubing. I was able to recover some ash from the generator, presumably from the burnt carbon deposits I was attempting to remove, and the fuel now flowed freely - albeit exiting from the new holes! so with more care this may well work.
 
 So it now looks like I have no choice but to purchase a new one now. About ten years ago I bought a generator via a local outdoor shop. It then cost me around £10.00 I've recently searched the web for a supply here in the UK, the best price I could find was £12.95+carriage but they had nil stock. So I searched again, this time world wide. Found a place in the USA (via Amazon.com) that was selling them for $7.49ea (£3.71ea) so I ordered two, had them shipped to a friend of a friend in the USA who in turn send them onto me, as the company won't ship outside the USA
$14.98 goods
$9.98  shipping and handling
$4.20  onward shipping
$29.16 Total (£14.45 (£7.23ea) at the time of transaction. Sept 06)

It only took ten days from ordering to receiving the goods, and what's more the shop here in the UK still has nil stocks.

 Is this yet another case of 'rip-off Britain'? lets not go there, today ;)

 
Coleman Stove in operation
 
 More technical information can be found here on how these stoves work.