Petromax 829B is it original?

Should I keep it installed? I'm going to burn only kerosene.

 

Here is the foot valve I installed earlier. This is the order it was installed as well. Does anyone see any problems?

 

The piece of brass gauze was installed in all petrol/gasoline lamps of the German and Swiss armies.It served as a filter.

 

I'd leave it in, it also helps keep carbon particles from flowing down to your foot valve disrupting the seal when shutting down. Removing the pressure keeping the kerosene in the generator during operation will make the unvaporized remnants to flow back down.

 

@Dashwood @Reinhard
I'll keep it it. Are there any issues with my foot valve assembly?

 

I see nothing wrong.

@Gilbert

 

The foot valve looks ok to me. But does it operate 100% ?
So without pre heating and on pressure where does the lantern leak?
Because you have several point found and solved now.
And when you open the valve (outside) do you get a fine spay line of fuel out of the jet ?
Without pre heating you should only get fuel, with proper pre heating you only get gas, no liquid fuel.

In all cases there should no fuel leak from underneath the jet.

 

Okay I'm putting it back together now. I've got the needle set right at 1mm.

I couldn't get the mesh filter back in the generator.

I have it all back together. No more leaks, just a fire ball.

 

Check your J-tube height, @Gilbert

Your lantern should have included a wrench which is 14.2mm wide at the end.

Use this diagram which will show how the wrench should be used to set the air gap.

 

@WimVe,
The foot valve feels like it's operating properly. It was lined up correctly and moves up and down as it should.

I'm not leaking fuel any more. I get a find jet spray of fuel from the jet.

Interestingly, the only nozzles (nipple?) that don't leak are the ones that came with the lantern. The new petromax #50 nipples leak.

 

@Gilbert

If you can, I'd strongly recommend changing the straight vaporizer with a looped one as the straight one doesn't absorb enough heat to keep the kerosene boiling and leaves it susceptible to flickering and flaming even from a slight outdoor breeze. Plus the jet on the straight benzine/gasoline generator is bored wider at the oriface for gasoline, kerosene orifices are alot smaller.

Gasoline oriface will let out too much kerosene increasing chances of flameups.

When changing to a kero vaporizer, make sure to switch to the appropriate needle too as you'll damage the kerosene jet, reaming it back to gasoline size.

 

@Dashwood

I'll change those parts out.

One thing about the gap between the jet nozzle and the J tube. I can't get the gap any wider than 12.5mm. The mixing chamber won't allow me to adjust any higher.

 

You'll have to unscrew the mixing chamber on your jtube to give your tube more slack for you to raise the tube, the tension on the tab where the tube goes through should be enough to keep the mixing chamber from moving excessively. If that tab isn't providing enough support against the mixing chamber to keep it from spinning or moving, carefully bend the tab downwards and reinstall the chamber again and the natural spring tension should keep it reasonably placed.

Do not excessively tighten the mixing chamber, tighten it enough until you feel some tension in the tab.

 

@Dashwood
I will adjust that next.

Here is what I have after changing the needle and nipple again.

No more flames. Could the dim mantle be because mine is blackened and full of spot?

 

What about mixing kerosene with white gas? Will that help the straight generator work better?

 

A proper burn will slowly burn away the spots on the mantle. If not, careful use of a butane/propane torch around the mantle should have the same effect.

Amish mix as you described should help and it popularly used in kerosene lanterns, notably Coleman's to speed up the preheat. Honestly I would be wary of making a more volatile mix for a petromax due to reported mishaps back in the Bundeswher back in the 50-60's since petromaxes lack any of the safeguards we see in Coleman, banking on kerosene's relatively to be less volatile. You wouldn't want to vent a lantern running gasoline to shut it down, right around a bright burning flame source would you?

 

@Dashwood

No I would be terrified haha. Is the Amish mix considered unsafe to use the vent in the fuel cap to shut it off?

My next purchase will be a Preston loop. I learned a lot about the petromax. Im sure the next one I get won't be such a nightmare to fix.

 

I'd recommend against it. If it has no positive shut off like Colemans and it has a bleeder cap, Kerosene is the only way to go in my opinion.

 

I'll focus on getting a Preston loop carburetor.

This is what it looks like now. It sputters and when it sputters, the mantle is momentarily engulfed in flames.

I think I'll wait until I get the Preston loop before I try anything else. The mantle is starting to turn white again.

 

Congratulations for sorting the leaks out. Visible leaks won't be awfully difficult to seal. Locating the source point is at least 50% of the work done. .
At this point, it is most important that you should check and resolve why the J-tube inlet air gap cannot be adjusted any wider than 12,5mm.
On both the 300/350cp and the 5000cp lanterns, 12,5mm is almost like a 'NO-NO'.
You likely won't get the optimum air-to-fuel ratio for it to burn any much brighter that what it is doing now.
On other things,..
Do you happen to have any 300/350cp jets/gas tips and needles? If you have them, they'd likely work better under the your lantern's current conditions. Those new jets or gas tips aren't always well-matched to older devices. Until you find a Preston loop type generator/carburretor, it'd be easier to use the 350cp jet-needle pair temporarily on the straight vaporizer. If you don't already have any such jets at hand, forget this suggestion for now.
The 500cp jet-needle pair should still be ok, even on a straight vaporizer...just a tiny bit trickier to optimize it. You should check again that the needle is ~0.23mm(0.009") in diam. The jet orifice is ~0.24mm(0.0095"). That's for kero devices.

 

There is a reason why the J-tube has such long threads on the burner side, you unscrew it give the tube enough slack to raise it to proper height, the tab where the mixing chamber presses up against what holds the chamber in place by tension once everything is adjusted. I had to do this on my genuine 1960 petromax with all original parts.

Once the gap is set, you tighten up the mixing chamber until you feel some tension from the tab, from there the chamber is held in place by friction and tension on the tab.

Despite not being fully threaded in, I never had any issues with leaking vapor or fumes.

 

Yes, you need not always have to screw-in the burner holder to full on the J-tube.
Just enough turns and some means to reliably seal or prevent them from falling off.
In my opinion, ensuring the optimum air gap would a more important parameter.

 

@MYN

Luckily the J-tube normally has enough run of threads with very little play that the burner doesn't wobble and enough of is engaged that it won't fall loose.

 

@Dashwood
You might want consider putting some sort of muffler cement or wrapping a piece of ceramic fibre string around the threads in order to beef up some confidence that it is tight enough on a later date.

 

Hi all, I adjusted the air gap to its proper dimension. My mantle burns dimly, but at least I don't have any leaks.

Everything is adjusted properly as far as I know. I'm going to order the Preston loop carburetor and see if that helps.

 

Let it run for a bit, the mantle should clear up.

 

@MYN
I don't have any 300/350cp gas jets. I can get a new carburetor from Britelyt it's a thicker version of the original. Would that be a detriment? I'm starting to understand how much hotter the kerosene needs to get vs white gas. What do you think about it? I think I asked this earlier, I'm just looking for more opinions.

 

@Dashwood
Are the petromax 829s dimmer than the the coleman 220s?

 

@Gilbert

A properly tuned 829s would make a 220 look like a nightlight you plug into the wall.

I have here a propane dual mantle which should be identical to a 220 in brightness next to a Chinese production Petromax 829 pictured below. You be the judge.

 

Wow that is impressive. I can't wait to get mind running properly.