Lurking member speaks about a newly acquired Svea 123

I have been lurking here for awhile, learning what I can. Today I acquired my first Svea 123 and thought I would post some photos and ask a question.

Based on what I have read here, I think this is from the early 70s, and is one of the early Optimus "orange and lemon" models. It appears not to have seen much use, although I could be mistaken.

My question is whether there is any significance to the fact that the valve is located to the right of the filler cap as opposed to the left, where it usually seems to appear aligned with the "1". Does this suggest that it has been improperly reassembled by a previous owner? Is this orientation a cause for concern?

Before testing the stove, at minimum I plan to do a leak test in water, and also to replace the filler cap washer and the SRV pip whenever I can track down or improvise the necessary tool and parts. I did remove the filler cap and pushed outward on the SRV; it had been stuck but popped loose and easily sprang back and forth as I applied and released pressure with a bit of wire.

Thank you for your time.

 

Welcome.

That’s a good find.

I would do the “dunk” test and if it doesn’t leak at the riser to tank connection, leave it as found. Then I would light it and run it without fitting the brass cage and observe the tank at that point to make sure there’s no leak under operating conditions.

A few Svea 123 turn up like yours, with the same resultant speculation.

Cheers

Tony

 

Looks unused, one of mine w/o the ribbed vaporizer is clocked to the right like yours.
Duane

 

Glad you have read up on your stove, good for you. From your photo looks like the key is hitting windscreen and not lined up with valve body. When windscreen is twisted in full locked position valve should be centered in wide opening. Orientation no big deal as long as key lines up. Good observation to catch that it is aligned different than normal.
Have fun with your new stove and use outside. Daryl sunny SoCal

 

Thanks all! Dunk test confirms the need to replace filler cap washer and pip. I know a couple places to obtain those (Fettlebox!). The challenge is to find or fabricate a penta-wrench. The one US ebay seller I found won't ship to Canada. May have to dig out my file and start improvising.

No bubbles observed at riser to tank connection but of course would want to retest that once aforementioned replacements completed.

 

@MrCanoeHead I made a penta wrench using an old Allen key works a treat and was not a mammoth task good luck.
Cheers Nick

 

Bernie Dawg might send you one if he has one. An ebay seller Varga(?) makes them too.

 

Thanks for the suggestions; they are appreciated. I ended up filing one out of a bolt and got the SRV out. I will put a few photos of how I did it in the Fettling forum just in case anyone else might benefit. It's not that profound but I have no experience with such things and it took a bit of trial and error.

 

search Five-Point Star Screwdriver Robertson / Triangle Types Bits Set 1/4" Hex Shank on ebay then choose B1 3mm

 

Careful, often those tips are rounded and will damage the screw in the cap.
The best tool for the pip had a taper and sharp corners to fit well.

 

An update on this stove. I ended up making my own wrench and posted info about that in another thread.

I ordered the fuel cap washer and SRV pip from Fettlebox, along with a few other goodies. I received the package a few days ago - very nice and well-packaged, neatly labeled. Thank you very much Ross!

After replacing the fuel cap washer and pip I repeated the dunk test several times and detected no leaks. I did see a bubble come up from under the fuel cap, as well as a small one from within the SRV pentagon. At first I thought there might be a leak but came to believe it was likely just air trapped beneath the cap and within the SRV pentagon as I immersed the stove. There was no stream of bubbles and I did hear some pressure release when I removed the fuel cap immediately after the test.

I also removed the nipple and wiped out a bit of black fouling below the threads that hold the nipple.

I moved outdoors, stove and fire extinguisher in tow. I lit the stove and let it burn for 15 minutes or so. The daylight was so bright that neither my eyes nor my camera could perceive the blue flame but my pot containing ~600ml of water was certainly heated, although not boiled. The air temperature was 3 Celsius (~37 Fahrenheit). The stove had been fuelled allowed to come up to room temperature indoors for several hours before I tested outside.

I re-lit the stove in the dawn light this morning to capture a photo.

My next challenge is that the stove seems to have a limited range of output. At the very low end I can get a candle flame, and then as I open the valve it quickly becomes a moderate blue flame which seems to be the best it can do no matter how much wider I open the valve. Here is a video to demonstrate.

I won't be able to investigate further until tonight, when I plan to examine the valve spindle after removing the packing nut. Thus far I have not done that, nor have I removed the vaporizer from the tank to examine the wick. I did briefly put a 12mm wrench on the vaporizer but was not able to budge it. I do have a vise that I could use to hold the vaporizer while I turn the tank but am not inclined to try that until I rule out other potential causes.

I would welcome any thoughts about this. I also realize that I don't really know what to expect the normal valve range to be. How many turns of the key are typically required to go through the full range from smallest simmer to full burn?

Thanks again.

 

The stove should burn with much more vigor than is shown in your video. With the 123 (not R) model turning the valve past about one turn does not do anything. On Bernie Dawg’s Bluewater Stoves website he has a full video about dismantling, cleaning, and reassembling the 123. There is not that much to go wrong with them. If you have replaced the fuel cap washer, you are likely ready to disassemble and clean the burner. The wick may be suspect, which is inside the fuel tank. I am assuming you have already pricked the jet?

 

Hi BradB,

Yes I did prick the jet. I will proceed with full dismantling, suspected this was inevitable. Certainly educational!

Thanks for confirming the valve range and expected intensity, consistent with what I thought I'd been seeing in various online videos. This is my first real-world experience with a 123, so it's good to have confirmation from someone who knows!

 

In that kind of cold, breezy? conditions, it may never get up to full steam. In cold weather, even with a windscreen, it may take longer than you want to get full power. Tank has to get HOT to get to a working pressure. I would try it in the house or somewhere dead calm. At the very least you need a good windscreen. And prick the jet again!

 

A couple simple things to remember, when filling, leave an air space in the top of the tank, and open the fuel cap and then close it to equalize the tank pressure before lighting.

 

@MrCanoeHead

Is this helpful?:

Svea 123 Disassembly

Cheers

Tony

 

Thanks Majicwrench - that makes sense. We are supposed to have warmer weather this weekend; I will give it a try then and try to shelter out of the wind.

IvanN - thanks for that reminders, I think that I had a good airspace but will make sure to fill only 2/3 or so next time. And I did not loosen the cap before trying so definitely need to develop that habit.

Thanks Tony that is certainly a helpful overview.

I was only able to slightly budge the vaporizer (10-15 degrees rotation counter-clockwise) with the stove upside down in a vise. I'm reluctant to put much more force on it; I suspect I will bend something. I tried penetrating oil (Liquid Wrench) and also heated the tank with a heat gun then immersed the vaporizer portion in ice water. Two cycles of this to no avail. I wonder if the deposits inside the tank give a clue as to what has caused the vaporizer to be so badly seized and whether I should try to remove them somehow. Perhaps I should also try heating the tank with a torch? I have a small propane torch for sweating copper plumbing fittings.

I am inclined to leave the vaporizer alone for now and wait for warmer conditions expected this weekend and to try again outdoors out of the wind, making sure to leave airspace and loosen/retighten the fuel cap immediately before trying it.

If it works better in those conditions, perhaps I should leave well enough alone with the vaporizer. Although it would be ideal to be able to check and maintain the wick.

 

@Tony Press , nice tutorial. Brad

 

That's some nasty looking stuff, that does not bode well for other parts...like the wick.

 

Please be careful, if you are using a gas torch. No one wants to hear that this action has caused an ignition.