Hi everyone, I'm new here and I am looking for any kind of advice from the experts. I recently purchased a Coleman 503 stove that would not fire, I could hear it hissing so I knew it was getting fuel. I ordered the parts I thought was the cause, a new generator tube, a new bunsen and a burner assembly. It did fire up briefly but seemed to loose pressure fast and now I can't get it to fire at all but can hear and smell the fuel. I dissembled everything and tested the parts, when I got to the valve assembly I opened the valve and it was spitting liquid fuel, I don't think this is normal but I don't know for sure. So my question is has anyone else experienced this or know what the cause may be? I'm thinking that it's between the valve assembly and the valve regulator assembly and perhaps a new pump assembly for the pressure loss. Thanks for listening
Hi, Jeepdriver. Welcome to CCS! I'd check the fuel cap, if I ware you. Any leak there will cause a slow to fast leak of pressure. Good luck, and God Bless! Every Good Wish, Doc
Check for cobwebs in the manifold too. As Doc says a leaky tank cap also may be the culprit. The pump shaft also has to be screwed on tight after pumping. Ron
Welcome to the forum, Sounds to me like your fuel pickup on the bottom of the fuel/air tube is clogged. You will still get air from the top of the tank, but no liquid fuel. It will still smell like fuel of course but will be way to lean to run. It will also deplete the air pressure in the fount quickly. You have to pull the fuel valve, which will require complete disassembly more than likely. Then take the outer tube off the fuel/air tube and clean the gunk off and out of it. A quick test is to pull the fuel line off the cleaning/regulating valve and open the valve. This may be enough, with the increased volume of flow, to pass the blockage. Run the valve through its full range while maintaining pressure. But before we get ahead of ourselves, make sure there is plenty of fuel in it first. I'm basing my diagnosis on the fact that you don't mention seeing liquid fuel leaking anywhere. John(Presscal) has an excellent 502 teardown photo montage on HERE . Keep us posted on your progress. Mike
I would have to agree with Toonsgt. It sounds like the fuel pickup is clogged inside the tank. Old fuel varnishing up could do that. Before taking it apart you can try filling the tank with denatured alcohol and let it soak for 24 hours or longer. Shake it around every couple hours or so. You should be able to pull most of the gunk out this way. When you try relighting you may have to open the valve up more then 1/4 turn as the spring can compress with age. Good luck, Ray
Welcome on board, Jeepdriver, When you say it was spitting liquid fuel from the valve assembly, I am not sure what you mean. When you disconnect the curved copper tube from the bottom of the generator assembly, can you get liquid fuel come out of the copper tube when the valve is open? If so, the fuel pickup system is OK. If not, and the fuel only sputters out when you remove the valve shaft, try to blow air through that curved tube. Yonadav
Thanks to all who have replied, I will try to keep you updated as I go. As of right now I have totally disassembled the stove and I will be cleaning every part, so far I found that the fuel/air tube on the valve assembly was extremely dirty. When it was assembled it held pressure until I opened the valve then it almost seemed like to much pressure was being released then in a matter of seconds it would drop to little or no pressure at all. When I tested the curved copper tube coming from the valve assembly that attaches to the bottom of the generator assembly it was spitting a mixture of fuel droplets and air and it seemed to continue through the generator and into the bunsen tube. I will get it back together and see what happens. Thanks again all.
These stoves do not hold pressure worth a dang when there is only air in the tank. With fuel it will last near to the end of the fuel supply. lance
Update, as you know I took it apart and cleaned every inch of each part then I put it back together, I filled it with fuel pumped the @#*$ out of it light a match and it works harder then most people I know. The best stove ever!! Thanks for everyones help
Super job! Now post some damn pics of it running. LOL. Really, we all like pics of stuff that makes blue flames. Mike
TTIWWP - this thread is worthless without pics! Flame shots! Flame shots! Flame shots! :-) Love the 502 and congrats on getting a classic back up to snuff! Now you have to find the heater, plastic case, aluminum cookset, and the even rarer 502 cookset pan grip! (still looking for an original grip, and no, I'm not gonna buy one off ePrey - may have to make my own!) willie (long-time 502 user)
Great to see it on fire again, the 502 is a great stove and I keep one in my camper as back up. In Canada I use one with a heat drum when ice fishing and it along with a Coleman 222 mini lantern. They do a great job keeping the shed warm.
