Stove help for a Svea 123

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Diamond-x
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Joined: Wed May 09, 2012 8:45 pm

Post by Diamond-x »

My father gave me a Svea 123 backpacking stove in 1979. I wiki'ed it and found they started making these in 1955, he bought it new and used it in the Sierra's for years. It kinda works but spits little bits of soot. It seems to need a thorough cleaning.

Are manuals available for these stoves?

How would I clean it?

Should I seperate the stem at the tank, extract the rope and clean the tank?

I boiled a cup of water in 7 minutes, seems like it should get hotter, it was also very hard to start.

Thanks!
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atomicoyote
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Post by atomicoyote »

Just saw this post so thought I'd bring it back up. Maybe Hikin Jim might see it and give you a few ideas. I've got an old SVEA 123 too, and the design hasn't changed. There used to be a shop in Tustin that sold parts for older stoves, but itsgone out of business. The 'Optimus stoves' website has a simple downloadable manual for it on their website. Plenty of videos on the internet, too.

They usually don't need any maintenance besides removing the old fuel if you've stored it for a long period. I just empty the old stuff, fill the tank with isopropyl alcohol (acetone or another solvent should work, too), let it sit for about 2 hours, then drain it and let the fumes air out before filling with fresh fuel.

Most white gas stoves I've used have their own 'peculiarities' when starting, and the 123 is no different. When you try to light it, be sure to prime it first to increase the the vapor pressure in the fuel tank so it'll drive the fuel up the wick. You can use a little bit of fuel in the indentation where the buner tube comes out of the tank (putting your hands around the full tank while the burner valve is open will drive fuel out and it'll drizzle down to the indentation), or just use a dab of 'fire paste' gel on top of the tank. Either way, light the primer material and let it burn so that it warms the tank (and fuel). After that its just open the burner valve and light it, adjust flame as needed. The radient heat from the burner is usually enough to keep the tank warm. And don't enclose the stove too tightly to conserve heat, as lack of ventilation can cause the tank to overheat and possibly rupture. Pretty simple.

They don't have a big flame, and they are not made to heat a big pot of water, so the long 7 minute boil time is probably close to normal.
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Hikin_Jim
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Post by Hikin_Jim »

Diamond-x wrote: My father gave me a Svea 123 backpacking stove in 1979. I wiki'ed it and found they started making these in 1955, he bought it new and used it in the Sierra's for years. It kinda works but spits little bits of soot. It seems to need a thorough cleaning.

Are manuals available for these stoves?

How would I clean it?

Should I seperate the stem at the tank, extract the rope and clean the tank?

I boiled a cup of water in 7 minutes, seems like it should get hotter, it was also very hard to start.

Thanks!
Cool beans!! The Svea 123 is one of my all time favorite stoves. There are two basic versions: One with a built in cleaning needle and one without. Which version do you have? Got a photo?

7 minutes for a liter would be OK, but not for a cup. You may need to replace the wick or the cap gasket or both. You may also need to clean the jet if the version you have doesn't have the built in needle.

Again, which version do you have, and let's take it from there.

HJ
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Diamond-x
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Post by Diamond-x »

I don't have a photo of it. It's all brass and the valve points down, so I think it is an original version without the cleaning needle.

I got rid of the 20 year old white gas and refilled it with a fresh vintage. It lights a lot easier now. I also took the tip off with the supplied tool (which doesn't have the cleaning wire) and cleaned it with a bristle from a wire brush.

The valve leaks and will light up once the stove gets humming, kind of dangerous. I unseated the valve and tightened up the collar, seems to have helped.

I appreciate any other info about this stove and it's maintenance.

Thanks Jim and Atomicoyotel!
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Hikin_Jim
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Joined: Thu Sep 27, 2007 9:04 pm

Post by Hikin_Jim »

Diamond-x wrote: I don't have a photo of it. It's all brass and the valve points down, so I think it is an original version without the cleaning needle.

I got rid of the 20 year old white gas and refilled it with a fresh vintage. It lights a lot easier now. I also took the tip off with the supplied tool (which doesn't have the cleaning wire) and cleaned it with a bristle from a wire brush.

The valve leaks and will light up once the stove gets humming, kind of dangerous. I unseated the valve and tightened up the collar, seems to have helped.

I appreciate any other info about this stove and it's maintenance.

Thanks Jim and Atomicoyotel!
If the valve slants downward, then indeed it is the orginal type, the type that came out in 1955. You did the right thing in cleaning out the jet orifice, using fresh fuel, and tightening the stuff box (but don't overtighten).

How long is it taking to boil a cup of water now? You may just need to run it for a while to burn off any gunk, but don't ever run it until it runs out of fuel. If you run it until it's empty, you'll char the wick.

If you're still getting long boil times, I would replace the gasket on the fuel tank cap as the next step.

HJ
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Diamond-x
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Post by Diamond-x »

Hikin_Jim wrote:
Diamond-x wrote: I don't have a photo of it. It's all brass and the valve points down, so I think it is an original version without the cleaning needle.

I got rid of the 20 year old white gas and refilled it with a fresh vintage. It lights a lot easier now. I also took the tip off with the supplied tool (which doesn't have the cleaning wire) and cleaned it with a bristle from a wire brush.

The valve leaks and will light up once the stove gets humming, kind of dangerous. I unseated the valve and tightened up the collar, seems to have helped.

I appreciate any other info about this stove and it's maintenance.

Thanks Jim and Atomicoyotel!
If the valve slants downward, then indeed it is the orginal type, the type that came out in 1955. You did the right thing in cleaning out the jet orifice, using fresh fuel, and tightening the stuff box (but don't overtighten).

How long is it taking to boil a cup of water now? You may just need to run it for a while to burn off any gunk, but don't ever run it until it runs out of fuel. If you run it until it's empty, you'll char the wick.

If you're still getting long boil times, I would replace the gasket on the fuel tank cap as the next step.

HJ
Thanks Jim, It hasn't been run empty as far as I know. The cap seal seems fine and doesn't leak at all. I'll time a boil when I get back from Hockett meadow!
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Hikin_Jim
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Post by Hikin_Jim »

Diamond-x wrote: Thanks Jim, It hasn't been run empty as far as I know. The cap seal seems fine and doesn't leak at all. I'll time a boil when I get back from Hockett meadow!
Hockett Meadow? Nice! Are you going in from Atwell Mill (north), from the west (Garfield Grove?), or the South (Mountain Home State Forest)? Nice area.

Press your fingernail into the tank gasket. it should leave a mark which should then gradually disappear. if you can't make an impression, your gasket is too hard -- even if you're not getting a leak. You'll be losing pressure and reducing your efficiency.

Have a *great* trip.

HJ
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Diamond-x
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Post by Diamond-x »

Hikin_Jim wrote:
Diamond-x wrote: Thanks Jim, It hasn't been run empty as far as I know. The cap seal seems fine and doesn't leak at all. I'll time a boil when I get back from Hockett meadow!
Hockett Meadow? Nice! Are you going in from Atwell Mill (north), from the west (Garfield Grove?), or the South (Mountain Home State Forest)? Nice area.

Press your fingernail into the tank gasket. it should leave a mark which should then gradually disappear. if you can't make an impression, your gasket is too hard -- even if you're not getting a leak. You'll be losing pressure and reducing your efficiency.

Have a *great* trip.

HJ
Hi Jim,

Gasket still has elasticity.

We'll be departing/returning from Atwell Mill. 10 miles 1,900 ft one way.

Thanks for the info.
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Hikin_Jim
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Post by Hikin_Jim »

Diamond-x wrote: Gasket still has elasticity.
You should be good in that case. When you get back, try running it for a while (without running it dry!) and see if it burns off some of the dross. Sometimes a stove will "settle down" after you burn through half a tank. If it's been sitting for a really long time, then you might have to refill and do it again. If you're still getting low performance, then you need to take a look at the wick with an eye toward replacement. A boil time on a liter of 6 or 7 min. is fine. The Svea 123 is solid performer (and a personal favorite), but it's generally not in the same performance category as stoves with a pump-pressurized tank.
Diamond-x wrote: We'll be departing/returning from Atwell Mill. 10 miles 1,900 ft one way.
Nice. Take photos and post here. Please. :)

HJ
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