G,,day . Coleman 249 scout , kerosene , Australian made . a couple of questions , I searched but could not find answers . does the vapouriser have any thing inside it ?? mine doesn't edit; possibly a jet pricker rod and mesh ?? also is there an exploded diagram or description of the NRV ??? and how to remove . I am presuming it may be the same as other coleman NRV,s . but I have never had to remove one of those either . cheers kerry
The 249 has the coleman shut off valve assembly. Be carefull you don't mess the slot up trying to get it out. Also the generator has a brass pricker rod with needle in end of it.There is also 2 coil springs one large and the other one fits inside it . Bob .
thanks Bob . I thought as much . looks like I had best get a correct tool for the NRV , and a new vapouriser or just the needle and springs , most likely sold as a unit . cheers kerry
Hi Kerry, If you have difficulty finding the 249 generator in Australia, you may be able to find a Coleman 201 generator for a much lower price. The cleaning needle / pricker rod is the same length and needle diameter. You can also easily make your own "springs" from brass or copper wire. Just roll the wire in a coil shape around a stiff rod or wire of about the same diameter as the cleaning needle shaft, stretch to about double the length and cut to the inside length of the generator tube, less about 1/4". Then make the outside spring in the same way on a larger former like a screw driver, and stretch. It should end up being an easy sliding fit into each other, the generator tube and around the cleaning needle shaft. The inner and outer springs should be wound in opposite directions, like left-handed and right-handed screw thread. It would be a good idea to clean the inside of the generator tube thoroughly first by unscrewing the jet or gas tip, and then carefully heating it to just dark cherry red with a gas flame. Then quench in water. This burns any carbon residue inside to ash and loosens the ash from the brass. You can then scour the inside by hand with a round file, drill bit or even a long screw. Be aware that quenching makes the brass soft and it will dent or deform easily if dropped or pinched. I have had fair success using this method on a number of different Coleman generators as these parts are very hard to come by in South Africa. The most recent price I saw for a new 249 generator from the US was about $23.00 plus shipping. Also, do not remove the pump non-return valve unless it leaks so much that it is difficult to pressurise the fount. Even then first try to clean it in situ by dissolving any gummy fuel residue by soaking with carburettor cleaner. A slight air leak past the NRV while pumping is acceptable and far preferable to damaging the valve, pump tube or fount while trying to remove it. -Phil
G,,day Phil . thanks for the info. I did check today with a local supplier . nothing much at all , I do need some other parts so I will get a complete one at the same time . it will have to wait a while before it gives light . cheers kerry
The way I clean my generators is to soak them in cleaning vinegar which can be purchased from Woolies. Then use a pipe cleaner. They come up like a treat. In fact I soak most of the parts in the vinegar. It cleans enamel, chrome, nickel and brass. You just have to ensure that they aren't left in the solution for too long It will eat away rust as well. Regards peter
Hello Kerry. Regards to parts might have some spares here . List of parts for 249 scout email me etc .Bob
@phaedrus42 can you give me an idea of the diameter of wire you need for each of these springs? I have a generator missing the springs. Thought I would give making my own a go before trying to source a new one. And what wire is best, copper or brass? Thanks John
I've used copper wire because it's a bit more malleable than brass and it's easy to find - I used the inner core of some heavy duty electrical cable which works very well indeed. As for the NRV tool, you can make your but it's time consuming plus you need a range of tools and a great deal of patience. I'd be tempted to buy one - the only reason I made my own was for the engineering experience. If you can unstick it, definitely do that.
Seeing that it's not exposed to oxygen that will cause flaky oxides to block the gennie, copper works just fine. 1mm should do for the inner spiral and 1.5mm for the outer. One is wound clockwise and the other anti-clockwise. Or should I have said deosil and widdershins.
I bought a NRV removal tool made by Mike Wells. It works wonderfully. They are sometimes available on the Old Coleman Parts website.
By basic design, the 249 generator coils aren't too different from those in the 237. As for the exact diametres for both the outer and inner coil wires, they don't really matter too much, as long as they could fit nicely into the generator tube. They should be wound in opposite helical directions with respect to each other. Otherwise, the supposed fuel flow dynamics and turbulence in the generator wouldn't be quite the same as the original. The inner coil should facilitate the centering of the pricker rod while the outer coil is necessary to keep the spacing between the generator inner wall and the inner coil. In addition, it might help to distribute the heat throughout the internals of the gen by both its mass and thermal conductivity. You can actually use other metals besides brass. Copper is also suitable but I find that it has a higher tendency to 'blacken up', whatever that is. It can't be oxidation since there's essentially no oxygen inside the tube. The diametre of the inner coil wire is smaller than the outer one.
Good Old English terms... my mum used to say widdershins now and then but deosil was new to me - thanks Phil! The blackening of the copper... could that be the small amount of water dissolved in the kero bringing an even smaller amount of oxygen with it? Just a random Thursday morning thought!
It could well be. I'd have some suspicions that it could also be due to the tendency of copper to react with the sulphurous compounds in kerosene at high temperatures. No deeper thoughts about any prevention means to that anyway. I'd just accept whatever way it turns out to be unless if it is loosely bound where it might pose some risks of clogging up the jet orifice.
