A question for the Coleman experts

I noticed that on my 288 CL2 one of the mantles was not as bright as the other, and it seems to be getting worse. Looking at it while burning I can see that the screen was glowing inside the burner cap of the offending side.

There is plenty of pressure and the fact that the other side is going well would indicate that the vapouriser is working too. The mantle is unbroken. What would cause this ?

Chris

 

Back burning? Are you using Coleman Fuel or kerosene? This is seldom an issue with CF lanterns so long as you've got enough pressure.

 

hi @MYN I am using the finest original brand new coleman fuel

 

You might want to check out the dim unit without the mantle. Is there something amiss with the burner's screen? Sometimes the wires burn out, leaving too large an opening. It might not neccessarily be for your case but it happens. Sometimes one of the burner tubes could be loose or having an opening at the wrong spot. That might slow down the flow towards the burner and create conditions favourable for an underburn.
There are others having more experience with the 288. Maybe they'd have a better idea.

 

I shall do that - I am not sure if the burner cap and screen are available as seperate parts - or even detachable for that matter. I see earlier Colemans have part numbers listed for them for cap and screen but on the 288 only a "burner assembly" is listed.

 

The inside of the burner tube may need to be cleaned.

 

Check the burner screen, use part of a wire coat hanger to clear out the burner tube and air tube.

 

Chris, I would be looking for an obstruction in the burner assembly. In the burner tube (as suggested) or above the tube in the burner head.

 

Agee with the clean the burner posts above. Use a bottle brush or frayed, stranded wire to clean inside the burner tube. Spiders love to put egg sacks in burner tubes and stove manifolds. Compressed air won't budge them, only mechanical methods will get them out.

 

I have had a good look. The burner caps seem to be fixed permanently to the posts. The screens are retained by washers and the end of the cap swaged over to retain them in place. The Screens were pretty gubby and I have cleaned them up. There are however a couple of areas of corrosion/damage - but not I hope enough to stop it working well.. I will test it out tonight and see what happens.
I have a feeling that a replacement burner assy in the UK will far outstrip the value of the lamp. If it does not work well there may well be some experimental metalworks ! I thought of dremmelling out the retaining washers and replacing the screens, and retaining them with internal circlips. Even if the temper of the circlip is destroyed it should still hold it in place.

 

Do you have pictures of the burner assembly? I think we would like to see it operate without both the mantles. That would give us a good measure if anything could be at fault. Could you find any blockages within the burner or tubes?

 

Ok - no blockages that I could detect, but due to not being able to take it apart I cannot gaurantee. But nothing rattled, or was dislodged by poking with varoius implements.
A series of photos as requested:

 

@Fireexit1

Does that last photo show that the right hand burner flame has diminished?

Could it be that your jet is shooting off centre, putting more fuel into one side of the burner assembly? Or that their is a restriction up top that means more fuel is getting to one side?

Tony

 

@Tony Press - yes - but with the valve turned to low. the "splitter" inside the burner body seem central, but I think the generator is a bit tired. This model seems to have quite a thin generator compared to later ones. It was bent and I had straightened it a little. The pricker is intact and moves freely, but of course the jet may be worn and throwing gas out of line. I had already ordered a new one from Canada so will try that before digging deeper. The previous owner told me he had spent more on globes than the cost of the lamp. His parents bought it for him as a teenager so he could practice/learn the guitar in the garden shed

 

Just realised the "splitter" to whch I referred was no such thing. It is just the weld seam visible on the bend on the inside of the burner assy.
I did however realise that I can rotate the generator. I did so - 180 degrees. and lit up. No different. I shall wait to see if the new generator makes a difference (I have had a look inside the old one and the cardboard is pretty black for 2/3rds of it's length)

 

Is it possible for you to remove both the burner caps, swap them over and then re-light them?
That way you'd know if the problem has anything to do with the caps.

 

They seem to be fixed rather than threaded.

 

The whole burner assembly is a one-piece? Oh my...you'd have a pretty tricky fettling job ahead.
Perhaps you could try immersing the whole assembly in some lye solution or some other liquids that could soften any foreign matter that might be lodged inside. It could then be easily flushed out later.
What's the tube made of? Brass, aluminium or steel? Any zinc plating?
No lye recommended for aluminium and zinc parts.
You should remove the burner, pump up the lantern and then release the fuel via the jet. See if the fuel stream is sharp and straight or skewed or anything like its partially blocked or leaking at that end.

 

They are steel, with some sort of plating. Maybe even aluminised ? I could try a citric acid solution I guess.

 

If the plating's nickel, lye won't harm it much. I know its hard to access the insides for a one-piece item like that. So one way around that is to soak it in something so that whatever foreign matter gets softened and eventually washes out.
You'd still need to check the fuel stream from the jet. Ideally, its straight and sharp.
Am I correct to say that the brightness of this 288 is supposed to be adjustable?
How does the mechanism work? It might even be at fault

 

Yes it is adjustable. New Schrader valve fitted. I have rotated the jet 180 degrees - if it was the jet not being straight causing the prolem I would have thought would have swapped sides. I think that there is no obstruction but the burner has a "bias" - which may not have been apparent when the jet/generator was new. Not sure when the new genertor will turn up but it is on it's way from Canada

 

Not just the jet or generator. I mean the stream of fuel out from the jet orifice. Is it shooting straight out sharply?
I've experienced that weak or low flow fuel streams would produce underburns. The fuel-air mixture would simply burn inside the tube instead of outside the burner cap.
I've seen this often in both kerosene and lpg burners.
Yes, sometimes there are biases and the preferred flow path in twin burners.

 

Hmm. I get an intermittent jet, interspersed with air/vapour. And a damp ceiling.

 

I don't think this to be an issue of the generator. If you turned the generator already by 180 degrees.

Is a subject about the burner assembly.
Either
You replace with new
Or
You disassemble with force, check interior, assemble with hard solder.

Something causing a flame flashback....behind the burner grid.

 

The burner tube with the glowing gauze is burning back, Is one side harder to blow back through than the other? You could try soaking whole tube assy and blast through with garden hose both ways

 

You need to do this outside. Its pretty strong.
Was the fuel stream straight? It needs to be ideally so. There should only be air bubbles interspersed with the fuel for the first few seconds after you open the release valve. If the bubbles were sustained, somethings not right within the fuel pickup or valve.
You'd certainly need to reinspect the burner assembly and thoroughly clear out whatever's not visible or accessible.

 

Well. This one is proving to be quite a challenge - and I have sucessfully rebuilt some "junk" in my time...
A day's soak of the burner in Citric acid seems to have cleaned more rubbish off the screens in the burner assembly.. Water runs equally through each side. If I blow down it there is no difference between the sides. However the generator won't produce a neat jet of fuel. It splutters. I had an old but servicable generator off a 285 - which has the same letter "p" on the jet so switched the jet over. No better. So - I took the valve assembly out again to look at the pickup. It looks OK and has no blockage.
However I did note that the graphite seal on the excentre stem is broken. In my petromax type experience this leads to fuel coming out not air leaking in, but I am running out of things to look at. Astounded how such a simple thing can be so elusive. Anyway I will now try find a Coleman graphite seal, just to take it out of the equation.

 

It should not splutter continuosly. What if you remove that generator and leave only the valve attached? Would that produce a steady fuel flow without the air bubbles? If it does not, you'd know that the valve block- fuel pickup assembly is problematic.

 

My understanding is that once the generator is hot, it's no longer liquid fuel shooting out the tip but gasified fuel. I don't think a generator tip shooting fuel out an an angle is the issue. That's a frustrating burner to work on since it's all pressed together and not takeapartable. Yes, I just said that.

Hmmmmm, I think you're on the right track cleaning each component as you work your way up. If you have access to a compressor, try blowing out each part opposite to the fuel flow to dislodge any bits of gunk.

If it's a wasp-mud dauber nest in the burner they can be real swines to remove. Soaking it in hydrogen peroxide can help loosen up the wasp mud and spider stuff and make it easier to flush out. Not sure whether the H2O2 oxidizes the bug saliva or what, but it does a nice job.

Mike.