425F Start-up Issue

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burnt bacon
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425F Start-up Issue

#1

Post by burnt bacon »

This is one from the 70's. When lighting according to the usual procedure, opening the valve, when lit the burner shows only a stuttering blue flame for a few seconds then goes out. This happens repeatedly until it decides to get going, with good fuel supply and gen functioning. It never goes into a tall yellow flame that would serve the purpose of heating up the gen.

One time I tried opening up the valve more and quickly realized it became flooded. Drained out the excess and did get to start. Either way when it gets going the main and aux burners work great, with good adjustable flames.

Haven't tried it, but it almost looks like if I used a torch to pre-heat the gen, then it would start easier, but I would rather it worked correctly and don't want to resort to pre-heating the gen all the time. Would add that this is outside in temps in the 30's, 40's, not sure that is the reason it won't flame up normally to heat the gen.

Thanks for reading and any response...
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Phredd
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Re: 425F Start-up Issue

#2

Post by Phredd »

It should not be the cold. You can always preheat the gen with a torch to make sure.

But is might be junk in the fuel. Every time you open the valve you move the pricker in and out of the orifice. And this might be cleaning out the orifice.

My approach would be to take the tank and gen out of the stove - pump it up and open the valve and see if you get a steady stream of fuel. If not then the problem is likely junk in the fuel or maybe bit of crap from the generator.

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Chucker
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Re: 425F Start-up Issue

#3

Post by Chucker »

Many directions sticker on the stoves directed the user to open the valve fully with the lighting lever 'up' to start. The keeps it from flooding typically but be ready to add more pumps to the tank. You eventually lower the flame of course and lower the lighting lever.

I have experimented with moving the lighting lever halfway down to the six-o'clock position for a bit especially if it's a bit chilly or damp outside. I like the results.
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burnt bacon
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Re: 425F Start-up Issue

#4

Post by burnt bacon »

Thanks for the input, guys. I dont think it's the fuel, comes from a fresh gal of high-price CF..., but will try the suggestion of testing the stream from the gen.

I asked the question to begin with since it works fine once it gets going, therein lies the mystery. Don't understand why it doesn't just flare up to get going. I'm opening the valve one full turn with the lighting lever up, by the book.
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zoomkat
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Re: 425F Start-up Issue

#5

Post by zoomkat »

" I'm opening the valve one full turn with the lighting lever up, by the book."

Is the fuel tank less than full when you try to light the stove?
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burnt bacon
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Re: 425F Start-up Issue

#6

Post by burnt bacon »

zoomkat wrote: Sun Jan 10, 2021 1:53 am " I'm opening the valve one full turn with the lighting lever up, by the book."

Is the fuel tank less than full when you try to light the stove?
yes, though when it was closer to full it did the same thing. If that is an issue, what do you suggest?
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zoomkat
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Re: 425F Start-up Issue

#7

Post by zoomkat »

"yes, though when it was closer to full it did the same thing. If that is an issue, what do you suggest?"

Well, with lanterns and stoves that have fuel control rods in the fuel pickup assemblies, generally lower fuel tank levels will result in less start up priming fuel being sent to the the generator along with the air. Lower tank levels may require some manual "priming" under lower tank level start ups.
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burnt bacon
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Re: 425F Start-up Issue

#8

Post by burnt bacon »

zoomkat wrote: Sun Jan 10, 2021 2:33 am "yes, though when it was closer to full it did the same thing. If that is an issue, what do you suggest?"

Well, with lanterns and stoves that have fuel control rods in the fuel pickup assemblies, generally lower fuel tank levels will result in less start up priming fuel being sent to the the generator along with the air. Lower tank levels may require some manual "priming" under lower tank level start ups.
Thanks for that insight. This would suggest topping off the tank, but not too much, before the next light up. The experimentation is neat.
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Stovie
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Re: 425F Start-up Issue

#9

Post by Stovie »

Assuming all the correct procedures and best practices about lighting are being followed, I will reiterate my usual suggestion to any and all who will listen about the importance of cleaning the pickup tube/air-fuel assembly. My much beloved 425 with the red legs worked "OK" but was much improved after a simple disassembly and cleaning. I would recommend this on any older stove on general principles. It is easy to remove the assembly from the tank with the aid of a shop vise. Think of how old school carburetors worked, with their many fine orifices, air bleeds, and jets and such, any sort of debris, gum or varnish will cause lots of trouble in the stoves too. Apparently it doesn't take much.
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burnt bacon
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Re: 425F Start-up Issue

#10

Post by burnt bacon »

Stovie wrote: Sun Jan 10, 2021 12:36 pm Assuming all the correct procedures and best practices about lighting are being followed, I will reiterate my usual suggestion to any and all who will listen about the importance of cleaning the pickup tube/air-fuel assembly. My much beloved 425 with the red legs worked "OK" but was much improved after a simple disassembly and cleaning. I would recommend this on any older stove on general principles. It is easy to remove the assembly from the tank with the aid of a shop vise. Think of how old school carburetors worked, with their many fine orifices, air bleeds, and jets and such, any sort of debris, gum or varnish will cause lots of trouble in the stoves too. Apparently it doesn't take much.
I will probably do this, since I have other stoves to work on and it's a good exercise to learn, would think.
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burnt bacon
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Re: 425F Start-up Issue

#11

Post by burnt bacon »

Happy Easter Gents...

Follow-up...brought the stove inside. Pumped a bit, tried squirting some fuel from the genny, no issues there. Hung the font, followed the lighting SOP, shortly after the flame started, it flamed up yellow flame exactly as it should... :!:

After a bit the flame blued as it should. Waited a bit, turned the lever down, the flame looked good. When I went to open it up, though, too much yellow flame appeared. I lit the other burner, yellow went away for both. Stayed that way pretty much for both, shut off the other burner, flame returned to the main burner until I turned the valve down some. After a minute of head scratching, adjusting the valve wheel, and the lever...ended up just adding more pressure and the stove behaved flawlessly.

I still think there was something about that sub-freezing cold that played into it before. With this outcome, don't think I'll be tinkering with it much more, at least not until I have a chance to get a few other stoves and lanterns going....Thanks, and best to all... ;)
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Majicwrench
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Re: 425F Start-up Issue

#12

Post by Majicwrench »

Sounds like it is working good.

The primary will yellow flame if valve open all the way. There is enough fuel being provided for both burners.
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burnt bacon
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Re: 425F Start-up Issue

#13

Post by burnt bacon »

Majicwrench wrote: Sun Apr 04, 2021 7:20 pm Sounds like it is working good.

The primary will yellow flame if valve open all the way. There is enough fuel being provided for both burners.
Ah...got it, thanks...

There could still a minor issue with the fuel/air tube, and I may get around to disassembling it.
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