Hey I recently bought an Optimus 8R that didn't have a flame spreader so i thought i'd have a go at making one. I used stainless steel from the lid of a broken kettle (it already had a curved lid so i didn't have to shape the cup in the centre of the flame spreader. I'm pretty happy with the results but the flame is slightly yellow at the tips once the burner is hot. I have tried changing the height of the flame spreader in the burner but that hasn't solved the problem. What i was thinking my be causing the problem is that the steel is very thin (0.5 mm) and heats up red hot very quickly. The reason i think it is an over heating problem is that if i turn off the stove then relight it before it can cool to a temperature below that which will vaporise the fuel the flame will burn blue for a while then go back to yellow tips once the flame spreader heats up again. (Sorry no pics of the flame as my camera did not capture it very well, with try and get some better pics later). What do you guys think? Cheers Luke
Luke, your pictures did not post. Did you put them through the image optimizer before you posted them?
Nice work! It looks a little high to me. How does it burn with a pot of water or kettle on it? If it blackens the pot or stays yellow you might have a enlarged jet/old jet. Jeff
I thought it was a bit higher than my other 8R with the original flame spreader but when i had it in a lower position the flame was the same. As for it blackening the pans i'm using, not sure cause the only thing i have used on it is a billy that i use in camp fires so already black. I didn't think it was a problem with the jet cause the stove doesn't seem to have had much work. I'll cook on some clean pans and see if they blacken and get back to you. Any other suggestions? Also i'm using shellite. Cheers Luke
Well done Luke. I think what Jeff said above is what could be why you are getting yellow flame. I would like to add that maybe the 'fingers' that attach to the burner bell might be a tad wide and could be restricting air flow thus restricting the flame petals a bit. Maybe a slightly narrower 'finger' on all four would provide the air flow required? Just a thought though. Have you tried the flame spreader from your other 8R to see if you have yellow flames on your new stove? atb, sam
Shellite is the right fuel. also known as white gas, naphtha, or Coleman fuel. It could be a case of the flame spreader being too thin but that doesn't seem to hurt other/newer stoves. Could be burning off some gunk in the tank or off the flame spreader or burner bell. I bet after some use the yellow tips will go away. Jeff
I just fired it up with the top section of the burner from my other 8R and had the same issue, still has yellow flame. I had a look at the cleaning needle and jet and they look new so maybe the previous owner replaced the old jet with one for a kero burner or something like that. I'll fire it up and let burn for a while and see if it changes. Is there any way to determine if the jet is the correct one for a petrol/shellite stove? Cheers
It could be a jet from kero burner or a later 111 but I doubt that. The cleaning needle would need to be changed too. Is the cleaning needle is set right?
There are some 8R's withe the yellow flame characteristic for one reason or another only two things come into mind, the jet or the flame spreader. The later either the circumference of the spreader is too big/small thereby the fuel air mixture is not proper. Also the material plays a factor in that. You just have to experiment till you get it right. Ron
I think the needle is set right but i am only a noob. I did re-set it cause i thought that it was stopping the valve from closing entirely but it just requires being closed fairly tightly. I also have a 111B which i was tinkering with (first classic fuel stove) and i thought i had done something wrong once i replaced the needle and jet cause it wouldn't close at all, so i readjusted the needle in relation to the cogs on the valve spindle (is that what it's called) and it closed fine after. So i think i know how to replace one, maybe. Cheers
I don't think now that the problem is with the flame spreader as i had the same result with the top part of the burner assembly of another 8R. I tried to copy an original flame spreader as much as possible so the diameter of the centre is the same as a genuine one. Is probably the jet then. Thanks for the feedback.
It might not be a big problem at all. A little yellow is nothing really. But if you want to order a new jet then try Basecamp or try these two near you.T W Sands & Co and ASSOCIATED KEROSENE & OIL LAMPS AUSTRALIA
Before ordering parts, I'd just run a couple of tanks of fresh fuel through it, It often does wonders...
I burnt a couple of tanks of fuel in my 8R and it seems to be working much better. The flame is not entirely blue but not far off. Thanks for the feedback. Luke
