Hi guys, long time lurker, first time poster here. I've just taken delivery of a British Army No 12, which was sold to me as unissued and unlit - there was nothing about the stove which gave me reason to doubt that - it looks pristine - aside from some minor discolouration on some of the steel parts that would be normal for a stove that has sat in storage. The case and paintwork is pretty much perfect. All accessories are present (jet spanner, funel etc). The pump leather seems in perfect condition, but the fuel filler cap definitely needs a new seal - it was a sod to get the cap off and you have to screw it down stupidly tight to get the tank to keep pressure. Finger tight was nowhere near enough. I had to clean the threads up a bit too - I think they corroded a little in storage. The NSN and the box both say the stove was made in 2000, so nearly 12 years old. I lit it today for the first time (for me and the stove) and it does run, though not perfectly. The first thing that struck me was "man this thing is LOUD!!!". The flame was a bit yellow - which I expected given the time in storage. I'm hoping that will settle down with a bit of use. The flame has a bias towards the front though, which concerns me more. I tried rotating the spreader plate to see if that was causing it and it wasn't, it stayed the same on a second burn. Any suggestions for getting a nice, even blue flame from this thing? Here is a short vid of it's first ever run... [media=youtube]0VBTeIO6HWc[/media] tia, Martyn.
Hi Martyn, welcome to CCS. The No.12 can be a great stove, and yes it is a bit noisy. Definitely not a "stealth" Military stove. If adjusting the flame-plate makes no difference to the flame bias you are experiencing it seems likely that there is a jet problem, perhaps a partial blockage or an irregularly shaped aperture. If using the cleaning needle makes for no improvement you should consider removing the jet and cleaning needle, giving them a check and a good clean, before carefully replacing them. There are instructions on the Site for the correct way of doing this: https://classiccampstoves.com/threads/8843 I actually used an Optimus 111 paraffin jet on my No.12 stove: https://classiccampstoves.com/threads/16802 I found that the aperture of the jet which came with my No.12 stove was slightly less than the 0.32mm diameter, of my Optimus jet. Hope this helps. Best Regards, Kerophile.
Hi Martyn. Ross, AKA Spiritburner, the Site owner makes and sells excellent Viton washers. The No.12 stove shares the design of the fuel filler cap with the Vapalux lanterns. If you send a PT to Ross he should be able to fix you up with a new filler cap washer....and a spare. Best Regards, Kerophile.
Thanks for the welcome and the jet suggestion does make sense, I'll take a look at it. Are 111 jets easy to obtain? Funny you should mention spiritburner, I sens a message to someone called spiritburner on ebay about replacement washers, I assume the same person? I had no idea he owned this site. I noticed that the fil;ler cap was the same size as a Vapalux but the threads on my M320 didnt seem to quite match and I didnt want to force it. It's good to know the washers are the same size though, I might get a few in as spares. I dont suppose the Vapalux pump parts match the No 12 as well?
1. Same man. 2. http://www.base-camp.co.uk/Optimus.html 3. #2509 Jet for stoves 8R, 11, 111, 123R, 199, 5R £ 4.50 4. Don't know about the pump parts of a No.12 and Vapalux and it is too cold and wet to go and find out. I believe that the No.2 pump may be similar/same as on No.12 Best Regards, Kerophile.
Thanks mate, looks like I need a new jet. I just took the jet out and it looked OK, gave it a bit of a clean and couldn't see any problems, but the hole is so tiny it's difficult to tell. I took the cleaning needle out too and the needle seemed to pass unhindered through the jet. I did notice there was a slight bend in the cleaning needle - is this normal? I'm guessing so as it sits at the back of the hole and therefore must rise through an offset. I do wonder if the slight bend in the needle is interfering with the fuel stream though? Is is possible to get replacement needles? I might pick one of those up at the same time - at least I'll have a spare. I'm quite pleased with myself, I reassembled it and it seems to work exactly as it did before, the needle pops up through the jet and pokes my finger and I still have the same range of control on the burner. Same problem with the flame pattern though. BTW, is it normal to get a gush of paraffin when you wind the cleaning needle up with no jet on the stove? Praise the lord for paper towels!
Just noticed that you say the jets are the same for SVEA 123R's - that's interesting - I have 2 of em. I might rob out a jet from one of em and test it on the 12.
On my No12 the needle is straight. If you get a gush of paraffin when you wind the cleaning needle up with no jet on the stove I can only assume there is some residual pressure in the tank. There is a great cutaway view of the burner unit on this post by 'lanevitt' Link which shows how the burner/needle/jet work on these style of stoves. The first group of pics show the jet but not the needle. If you scroll down there is a pic of the needle in place. Helped me alot in understanding my No12!
Hi, You can of course run your No.12 stove quite happily without the cleaning needle just to eliminate the needle and its carrier as the cause of the uneven flame pattern I too have found that he needle carrier does seem to sit very far back in the hole on some No.12s and I have seen that there was a large chamfer on one side of the needle carrier. However, the needle itself should, I believe, be straight. I also found that the Op.111 cleaning needle was not a "drop-in" fit, as it sat too far back in the hole and fouled the lower lip of the jet when you tried to raise it. Other No. 12 stove users have said that they have had no such problem and that the full Op.111 service kit provided a direct replacement. Another stove mystery! Best Regards, Kerophile. Best Regards, Kerophile.
Hi, here are a few photos of a rare No.12 Spare burner, which I acquired earlier this year for a Project: There was no jet and the cleaning needle and drive were "stuffed". The damaged original drive from the No.12 is at the top of the image, with a replacement drive from an Op.111 below. The Original No12 cleaning needle assembly, with broken needle is at the top, with a "dead" Op. 111 needle shown below for comparison. Note the large chamfer on the original No.12 carrier. Best Regards, Kerophile.
That's interesting Kero, thanks for posting. That chamfer would suggest that the cleaning needle sits further back and has to ride forward when cranked. The needle on mine was tilted forward slightly towards the teeth, which made me think it was supposed to be that way. I cant recall the chamfer though. I'm going to pull the jet & needle from a 123R later and swap it over, I'll take a picture of em side by side when I do it.
Yeah, I thought I had de-pressurised it, but there must have been enough in there to push the fuel in the pipework through when I opened the tap. Lesson learned. At least it's had a flush.
OK just tested the SVEA123R jet on it. I thought the SVEA jet hole looked a fraction smaller but it's hard to tell. The No 12 needle wouldn't rise fully through the SVEA jet, unlike the 12's own jet where it poped through and I could feel it stab my finger. It still worked, but it suggests the SVEA jet is a whisker smaller. Anyway, I still get the same front bias, if anything the No12's own jet burned a little better. I took a quick vid of the stove running with the SVEA jet, hopefully you can see the problem. [media=youtube]-v__S_hS7LY[/media] At least I know the original jet isnt the issue. It might well be the needle. I'll try the stove again with no needle in tomorrows daylight.
Hi Martyn. The No12 is a good stove. I use mine when ever i get the chance. Why dont you try yours with the correct fuel. It was designed to run on diesel, not kero. Then put a kettle of water on it and have a brew.You could also contact t.o.c (Tools of coventry), As they built it they may be able to offer some advice. Nigel
Very curious what the output is, when you discard the cleaning needle. Is the burnerhead in the center and flat?
Here's a pic of the cleaning needle though. You can see the chamfer as described by kerophile. The bend is far worse since I tried the stove with the SVEA123/111/8R jet. I said I thought the 123 jet looked smaller and the cleaning needle wasn't poking through. Obviously the 123 jet is smaller and the needle has been jamming in the cone and bending, rather than poking through the jet and cleaning it. I dont think this caused the original bend as the needle did go through the hole of the genuine jet. Although the needle is discoloured, you can see the teeth are in perfect condition, which would be normal for a 12 year old, but unused stove. This is the picture kerophile posted for comparison... The needle is out now and the stove is ready to run without it. I'll give it a blast tomorrow (providing it doesnt snow again) and see how she runs. Meanwhile, I'm going to try and straighten this needle without breaking it.
I've just done a quick burn test with the No12 and no pricker needle. I didnt video it because there is no difference. I still see a marked bias toward the front of the stove with the rear 1/4 of the burner showing very weak flame by comparison. So it's not the jet causing it and it's not the pricker needle. It much be the way the jet is hitting the spreader plate. I've rotated the spreader plate through every angle possible and it's the same regardless, so it's not the spreader plate itself. I'm wondering if there is a slight misalignment from the jet part and the burner bowl? If the front of the burner bowl was either a little higher or a little lower than the rear in relation to the jet, would that cause this effect?
I doubt a bit of a tilt of the burner mixing chamber would make the difference. Burners (especially the No.12 I've noticed) are often slightly misaligned and it doesn't seem to make a difference to the flame pattern. In some lighting conditions it's possible to see the jet stream, which would confirm whether it's not leaving the jet vertically, but at an angle. I've had that happen, though not with a Brit No.12. The solution was to put a really small chamfer on the jet outlet hole. The slightest burr at that point can deflect the jet. Worth a try? John
Thing is John, I've tried 2 different jets and I get the same forward bias off both of them. I can feel a slight burr of the jet though, so I might try lapping it with some W&D paper. I dont think it'll make much difference though, as I said I cant see the same problem occurring across 2 different jets.
