My Coleman® Camping Stove

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 claimed). 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 in fact 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 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 non-removable, 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 deposit in this area, as can be seen below the threads. Perhaps a yearly strip and clean in the way of maintenance is 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 micro-bore in the centre of the outer tube.

Spare parts list for the 533-700J dual fuel stove (first production 1/91)

220C1401 Filler cap 201019
220A6201 Pump repair kit 201030
533-5891[442-5891] Unleaded Generator 201066
508A5571 Valve assembly 201250
400-3451 Burner ring set 201239
425A3451[413C3021] Burner assembly 201462
400-5401 Grate assembly 201259
533-6151 Font/Tank
639-1091 Pump cup and clip 201070
400-5261 Burner box assembly 201257
400A1261 Generator bracket
400-0601 Screws, 6 per pack
200-6381 Check valve and air stem 201029 [1/4" x 32 ME Thread]
530A5071 Pump clip
508-7631 Carry case

Spare parts list for the 533-700E dual fuel stove (first production 2/92)

R533-615E Font/Tank
220C1401 Filler cap
508-5551 Valve assembly
413C3021 Burner Bowl
400-3451 Burner ring set
639-1091 Pump Clip and Retainer
200A6201 Pump Plunger
200-6381 Air Stem and Check Valve [1/4" x 32 ME Thread]
400-5261 Burner box assembly
400-0601 Screws, 6 per pack
400A1261 Generator Bracket
400-5401 Grate
533-5891 Generator Assembly
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 ;)

Generator

The stoves been running trouble free for about 10 years now, until today. I'm going away camping shortly so I thought I'd give the old girl a test run beforehand. Good job I did. I couldn't pressurise the tank, I checked there was fuel in the tank, checked the fuel cap was secure, the on/off tap was closed, yep all good. Pumping the plunger had no effect even with it in the locked off position. So I removed the plunger from the tank body for inspection. It looked alright and was lubricated. I added a little more oil and tried again, no joy. So I tried to open out the neoprene cup slightly by hand, then quickly re-inserted and pumped away. This time it pressurised the tank instantly and I was able to light it for a test burn. The burn was good but the pump again failed to add more pressure to the tank without me taking it out and splaying the neoprene cup out to form a seal with the pump chamber walls. If the cup was the older leather type an overnight soak in light oil might have been all that was required to restore it. But mine is the newer neoprene material and must be replaced. Coleman do a replacement washer and cup [9 in spares list] for the older leather type but for the neoprene type they sell a kit that consists of plunger, plastic locating ring, cup and washer [2 in spares list]. Also included in the kit are parts for older stoves/lanterns.

Replacement, Pump Repair kit. The items in the packet not attached to the pump are alternative parts for older stoves and lanterns and can be quickly changed if required.

I found this site with a little searching, the prices look reasonable as does the feedback so hopefully all your spares can be sourced in one place. If you can't see the item you require drop them a line.

The next part I want to have a look at is the non-return valve or 'Check Valve' (part 13 & 8 above) located at the base of the pump, inside the font itself. This little device holds the pumped air inside the font or fuel tank, or at least it should. Sometimes it is reluctant to move and leaks air past it. Also it can get gummed up completely with residue from petrol, again letting air leak past and out of the font. You could try carb cleaner or other solvents as I did, you may get lucky. I had to remove mine to get it clean. To do this I purchased a special removal tool, not knowing the exact size of the slot with which to extract it. I also found out the slot size varies on different models/ages. These things are not cheap but the right tool for a job is much better approach than rounding the slot off and having to drill it out. I bought one from this guy having watched his YouTube video. Once removed from the stove I was able to clean using a pan with some boiling water and a little citric acid.

This is the Check Valve Tool attached to the removed Check Valve. The tool comes with two threaded rods to fit older and newer models of stove/lantern.

source: https://oldtowncoleman.com/images/how-a-coleman-lantern-works-f2A.jpg

source: https://oldtowncoleman.com/images/how-a-coleman-lantern-works-f5A.jpg

One alternative to repairing a faulty Check-Valve is to adapt the Filler Cap using a Schrader Valve attachment, then use a cycle or car pump to pressurise the tank.
Although for safety reasons you should not attempt to add pressure while the stove is functioning/lit.

source: http://zenstoves.net/Petrol.htm#PumpPressurizedStoves

My stove has been around for many years now and the rubber seals are showing signs of their age. This particular stove has two of these, one is an O ring on the Check-Valve as seen above and the other is a seal on the filler cap.
These and many other parts are available from here.

More technical information can be found here on how these stoves work.